For me, the need to long rest is a big one. If the encounters were done right, you shouldn't feel like you need to long rest so much. The idea is to be able to fight hosts of monsters in between each long rest. So, if I am level 1 with a party of 4 and fight 32 Manes, I should at that point feel like I need to long rest. Instead, I fight 3 Imps and need to long rest because they are way too powerful for level 1.
Likewise, I fight 2 phase spiders and 2 ettercaps and need a long rest. It's the only encounter in the Whispering Depths before you fight the boss. So rather than fight a host of baby monsters as I work my way towards the boss, I am only fighting like a single encounter beforehand instead because I'm fighting super tough monsters. Thus, we have fight, long rest, fight, long rest, fight, long rest and super nerfed monsters so you can actually still beat them using the fight, long rest, rinse, repeat method.
Take the hag's lair. Big fight with redcaps that nearly kills you. Long rest. Enter her lair. Fight the masks. DAng! They nearly killed me. I guess I'll have to leave and long rest and then return to face the hag. Otherwise, I can't beat her because the 2... 2 only, mind you... previous encounters were too grand so I couldn't just continue on to face the boss.
I would not like to fight trash mobs, and certainly not in a turn-based game. As for me, such fights can lie where they are, that is in the garbage. Such fights are simply boring, much better are the more difficult fights with stronger enemies. The game should not waste the player's time by throwing a lot of pointless fights at him, where you might as well turn on automatic combat (the newest Pathfinder is more than 80% uninteresting fighting with trash).
I'm not talking just throwing trash monsters at players for the sake of XP'ing up. See? That's what so many don't understand about true D&D. There are no such things as trash monsters in D&D. There are so many monsters and so many varieties that you don't NEED to make every fight a big awesome boss fight.
If done right, the game should feel like a steady increase of bigger and better monsters as you go. Each monster is unique and provides a different flavor of combat.
Take the opening fights on the nautiloid. You are Level 1. Right now, what do you fight in BG3? Imps. Imps. Imps. Oh, and maybe some hellshogs. All of these should be way more than you can handle.
My suggestion is:
Encounter 1 = 4-8 Manes, AC 9 HP 9 +2 to hit. Much more appropriate for you to kill. Every 2 hits and one is dead. You should have a 75% chance, roughly, to hit each one. Look up Manes. They're small, pale, undead looking fiends who do 2d4 damage if they hit you. Not super tough, but for level 1 characters, they're still somewhat of a challenge in numbers of 4-8 depending on your party size.
Next encounter = maybe an imp and a few manes. The Imp is injured, so he isn't too hard to take down. Maybe he has 4 HP, which would require you to do 8 damage to kill it since he has resistance. A mage would really come in handy against the imp, or a cleric. Either way, you're still fighting a few Manes, but now you've got an imp mixed in for flavor.
Next encounter = fight a few thralls. They're not super tough, but they'll give you XP and provide flavor in combat. At level 1, anything's fairly difficult.
Next encounter = fight 4 thralls, but one has an intellect devourer inside. You kill the one with the intellect devourer, and it pops out and attacks you. This battle only occurs if you killed Us or you're straying from the helm objective. The intellect devourer is severely injured as well, so when it pops out, it only has like 4 HP. Thus, it only requires like 8 damage to kill it, and again wizards and clerics come in real handy here.
Next encounter on the helm = a dretch and 4 manes. Now you have SH and Lae'zel with you and maybe Us. A dretch is a brute with 11 AC and 18 HP and multi-attack with +2 to hit and a few special abilities. It is surely a challenge for level 1 characters, but it is more appropriate for them. With a CR rating of 1/2, two dretches would be a challenge for a party of 4 level 1's. So, 1 plus some manes isn't overwhelming. Still a hard battle, but it shouldn't wipe the players.
The point is, it's not trash mobs, it's appropriate monsters for the characters and their levels. THAT is the point I keep trying to make. Don't give me imps with CR 2 challenge rating that should be a challenge for a party of 4 level 2's, and you have to face 3 of them or 3 intellect devourers who SHOULD wipe the floor with your party unless you had maybe a party of 6 level 2s instead of a party of 2 level 1s.
