There are a lot of games without "send to camp" and "fast travel" in which your point 1 isn't a problem.
I guess it depends on your point of view. I'm all for immersion. I am. But annoying mechanics without real purpose other than to just annoy me is not fun. I think Skyrim, for example, is annoying when I become encumbered and have to either drop loot or walk super slow back to a merchant. Ugh! Go to merch, sell, go back, pick up the rest I left behind, go back to merch, sell...
Pathfinder's mechanics were kinda just annoying too. Drop all your heaviest gear, but when you leave the dungeon you can pick it all up again. Then dump the heaviest gear on the next game map and pick it all up again when leaving. Sure, you exceed some sort of threshold and have to dump just enough to be able to travel, so you might have to leave maybe a 100 gp worth of armor just to travel from the area, but it's still a lot of senseless, pointless item juggling. The end result is still the same. I go back to the merchant and sell all the useless junk for gold. What was the penalty for carrying too much? I, the player, was annoyed by having to juggle useless junk to try to make it work so I could get as much back to the merchant as possible.
That said, Pathfinder DOES have another penalty that makes sense. Encumbrance exhausts characters faster. Ah! Now we have a mechanic that makes some gameplay sense. This is one of the best solutions I could find. Too much weight starts to tire you and give your characters penalties to their rolls. The longer you are encumbered, the faster you become exhausted.
So, let's say we did something like this in BG3. Give characters Stamina Points based on Constitution score. Every time they Send to Camp or Fast Travel, a certain number of Stamina is lost, indicating that they manually traveled back to camp or the merchant or wherever, and time passed. The more distance traveled, the more Stamina lost. If encumbered when you fast travel or send to camp, more Stamina is used up. Then, when stamina is depleted, the characters start to suffer penalties. -1 to all rolls. -2 to all rolls when next exhausted level reached, etc. Short or long rest then recovers lost stamina. Food is expended when you do this, making food important to carry on you so you can short rest and recover stamina. Oh, and unlimit short rests and use food as the limit... And/or hit Dice.
This would make players stop and think and strategize. Should they just drop all that excess loot that only gives them 1 GP each, should they spend the stamina to lug it back to a merchant or camp?
