Again, IF DONE RIGHT, Random Encounters can be VERY good and fun. I agree, BG1 and 2 and Icewind Dale and Pathfinder, they all had baby, horrible, random encounters. There was nothing challenging or fun about them. They were just annoying. I'd still spam Long Rests, but I'd have to fight off random encounters three or four times, slaughtering tons of goblins or whatever, just to get a single Long Rest. It was annoying.
But I witnessed the Random Encounters in Solasta several times, and I've found them to be quite rewarding. You're roaming through more civilized areas, and the random encounters you run into aren't as bad. A group of bandits ambushes you while you rest, or you happen upon them on the road. Nothing huge, but gives you the sense that you're really traveling through a world and you randomly encounter enemies on the way, clearing the roads for travelers and such. I agree that the maps are fairly redundant, but then many things in Solasta would have been WAY better with more budget. They ran out of money, in my opinion, to REALLY polish that game and make it awesome.
But anyway, then while traveling through some bad areas, THAT'S when the Random Encounters became challenging and fun and gave variety to what you fight and face. Getting into a Random Encounter every time you long rest is not fun, but if it happens sometimes, at random, that can be fun. Like, "Holy Crap! While resting, some zombies came up out of the small hamlet nearby."
In BG3, they could still do Random Encounters during traveling and whenever you short or long rest. Certain areas have a higher percentage for potential for random encounters. So, you crash on the beach. Random Encounter chance is higher because you just crashed and there's a lot of activity in the area. Maybe you have a chance encounter with some surviving thralls from the ship. Maybe you encounter an imp that was brought over from the Hells. Maybe some crazy infected person, like you, tries to kill you because they're not good and they think by killing you they'll have a higher chance of survival. There could be a gazillion possibilities for lower level characters instead of running into 3 intellect devourers that aren't really intellect devourers because they're so severely nerfed. (Maybe even some panicked fishermen who you can talk down off a ledge so they don't try to just kill you. Maybe you could even talk them into getting out of there... or you chance encounter them fighting some intellect devourers and you're working to save them.)
Then you get to the other side of the nautiloid where there are goblin bodies. Random Encounter chance decreases a bit, but is still relatively high. After all, the goblin bodies are fresh. The goblin leaders sent out a bunch of them to check out the crashing nautiloid. Maybe some are still lurking around somewhere. You round a bend in the path and random encounter spawns two goblin scouts on the path. You head off the path to the south down the cliff and across the rocky ledge. Take a short rest. There, random encounters are way low. It's almost like a rest area with low chance for getting ambushed because you are off the beaten trail and it would be hard to get at you. You come back up and head to the dank crypt, face Gimblebock and his crew and Mari and Barton and their crew. Chance of random encounter is VERY low. Another good place to either short or long rest. You can literally shut the doors and lock them, and the dungeon is small enough that random encounters would be 0. This would make for the first good Long Rest Camp.
You clear the dank crypt and make your way back out. Chance of random encounters increases again (though keep in mind chances for random encounters should always be low... like 0-10% chance every five minutes of gameplay or every short or long rest. I'm just throwing those percentages out there, but the point is the percentages should be low all the time... not like random encounters happening constantly). You leave behind the crypt and find Lae'zel, etc. You're nearing the grove, so chances decrease again because the game is gearing up for you to fight the supposedly big grove gate fight to save Aradin. In the grove, 0% chance of random encounter. You could sleep there as much as you want. Make your way out again after the grove gate fight and random encounter chances increase again. The goblins are looking heavily for you and the weapon and the grove. So they're patrolling the area more. You head up to the Harper Lookout. Boom! Chance Encounter occurs. You surprise a group of 8 boggles. They're trying to avoid all the goblins running around. You could Persuade them to not attack you and let you check out the Harper Lookout Camp and be on your way, OR you could fight them.
You head down to the woods and random encounter wolves eating corpses near Bogrot (Moonhaven). You have the ability to use Animal Handling to chase them off, or they attack you. You try to short rest near where you meet Scratch. Random Encounter occurs and you get attacked by giant spiders that descend on you from above. (Note: All of these things don't happen in a single playthrough or in a single day, but maybe they happen at various days and times while you're playing the game.) The giant spiders surprise you, so some of your characters get webbed before they can even go. Suddenly, the random encounter turns into quite the deadly encounter that is difficult to escape from. Maybe next time you should try to return to the grove or something before resting. It's a dangerous world out there, and random encounters make that much more real.
By the time I'm done with BG3 EA currently, I feel like the entire world is pretty much dead. There is nothing left alive anywhere, and those who are alive are stuck in Groundhog's Day, repeating the same things over and over and over again for days upon days on end.
As for XP and Loot farming, if players are going to do that, more power to them. I would think most players would not want to bore themselves with such things, but if that's what they want to do in order to become gods in the game before they really need to be, that's their choice. I, for one, HATE grinding, so even if a game allows me to grind experience and loot endlessly, I'm not going to do it IF the game makes it so I don't need to. If I can beat all the enemies without grinding, HECK YEAH, I'm going to beat all the enemies without grinding, and THAT'S the kind of game I want to play. I don't want to play a game where I have to mindnumbingly grind in order to continue.
So yeah, if done poorly, Random Encounters would suck. I don't want them slowing the pace down too much or making it so that you become so high level just because you fought a bunch of random monsters that you can beat anything you encounter including boss monsters like Grym. But if they pepper Random Encounters into the game, THAT would spice it up and make it feel more alive.
You have wolves in the game already, and boars and bears and ravens and other such animals. Why not have us encounter more of them randomly? You have many types of monsters already in the game. Why not encounter more of them randomly to spice things up and make everything less static?
Imagine entering the bog on your first playthrough and encountering a giant toad. Then, on a different playthrough, you enter the bog and encounter stirges. Then, on another playthrough, you enter the bog and have to fight a banderhobb. Or maybe during one playthrough, you camp in the bog after fighting the redcaps, and you encounter 8 mites. Guess you should have maybe gone back to rest for the night at the grove instead of in a bog with a nasty hag living in it.
And yeah, I would LOVE for fast travel to be more like Solasta with the potential to be interrupted. I LOVE fast travel because I hate going through areas I've already cleared out and explored. But again, I only love fast travel if done right. In Solasta, you fast travel through a dungeon and a random encounter might interrupt you. Phase Spiders attack on your way back to the dungeon exit. I still fast travel at a super fast speed, but it's not me mysteriously teleporting from the middle of a dungeon to any fast travel point whenever I feel like it. I should not be able to fast travel from the middle of the Underdark to Moonhaven instantly. I should have to at the very least foot it to the nearest Portal with the chance of being attacked on the way, and then teleport to Moonhaven. That, at least, makes more sense from a world-building standpoint.
Oh, and unlike Solasta, I don't need to see a picture of my character moving at super speeds while fast traveling. I do like how BG3 just fades to black. You can still do this with Random Encounters. I travel from the middle of the Underdark to Moonhaven? Fade to black. Random Encounter occurs. Game determines where on the way to the portal I was attacked and puts my characters in formation on the path with enemies ambushing. Gricks attack! Dang! I guess travel in the Underdark really is dangerous. Yeah?
And, again, it doesn't have to be a fight every time. It can be, "You spot a group of carrion crawlers making their way on the path. Do you try to hide? Do you attack so that you gain Surprise?" Oh! Suddenly, Shadowheart's armor that gives her Disadvantage on Stealth is a LOT more of an issue. She might have better protection, but she's not as good at avoiding random encounters with that suit on.
