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...
I had the same problem ...
Until i find out that in Skyrim when you buy a horse and left him at start (or end, if you know where it is) of dungeon ... you then need to slowly walk just to that horse, and when you mount him no matter how much overburdened you are, you are able to fast travel again.

This become even easier with Dawnguard, when you learn to summon your horse.

Just saying.

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.
I like this idea! A lot actualy ...
I would only like to add that stamina should be used for regular traveling aswell ... i mean it would not make much sence if you spend *xy* points of stamina to fast travel from Grove to Goblin Camp ... but none for manualy travel the same distance.

But besides that +1!