How I would solve this is for players to have a limited amount of long rests, and only getting more after some milestone is completed, like after completing a quest.
Unfortunately, long rest has been problem in every cRPG I played. I believe that the traditional structure of a cRPG (handcrafted game with limited content) and the mechanic of resting (players choosing when to replenish their resources) are simply incompatible.
The problem with setting hard limit on resting is that it would require devs to make a hard cap on how many rests player should take per content. Set it too high and the limit in meaningless. Set it too low and players will get stuck and have to reload previous saves, which is not something you want in a narrative title.
You could tie it to difficulty, I hear you say, or let players set their own limit on resting, but that’s comes with its own host of problems. For example, if the setting says “this mode lets you rest twice before your reach point X” as a player I have no way of deciding if that’s something I want, without already knowing how difficult “point X” is, and how many resources it will require. Same applies to players deciding how much rest they will need. In addition, if “point X” is defined as “completing a quest” as OP suggest, than it is another variable - quests aren’t born equal, especially in Baldur’s Gate3. They vary in length, amount of combat, and resources required to compete. You also don’t tackle one quest at a time, so you might easily have to play through 4 quest with a resource cap and than complete them on after another.
Also some runs (no party run for example) may require more rests, and I don’t think players should be limited for pursuing playstyles they enjoy
There were some notable attempt to improve long rest in other cRPGs:
-Pathfinder: Kingmaker - like BG3, you required camp supplies to rest. However, no stash is available, so supplies cut into your encumbrance which while fairly generous, was still much more limited than BG3. Also you needed supplies per character in the party, so it nicely scaled with party size (and therefore less carry limit). Still, I hated this system, and that’s because a problem I mentioned above - it was essentially up to the player to decide how much resting they wanted to do in the dungeon, but it is not a decision they are capable of making without playing through the content first. While usually you can retreat and buy supplies/hunt in a wild, the game had some dungeons you had to complete in a single go. Fine on 2nd playthrough, or with a guide, but r very unpleasant experience on the first go, possibly resulting in hours of lost time, if players guessed wrong.
That is the only instance of “hard cap” that I am aware of, and most other cRPG go for “suggestion” route. While they don’t actually prevent abusing long-rest, they make doing so inconvenient, therefore encouraging a more sporadic use of the mechanic. At the same time they don’t block players who want or require frequent resting:
-Baldur’s Gate1&2 and other classing cRPG - resting in a dangerous area brings a likely hood of ambush. One can save scum their way through those, but it still can be time consuming (less so nowadays when game loads under a second). Still, a game at least suggests that you shouldn’t rest in a middle of a dungeon Willy-nilly, and makes it less frustrating to continue while you still have resources left.
-Solasta - you can rest at specific spots only - there is something unsatisfying about backtracking, so while one could go back to previous rest point and re-rest, pushing forward tended to be a more satisfying option. I never felt Solasta tested my resource management much, but it did get couple “bonfire! Just when I needed it” moments out of me.
-my favourite implementation so far: Pillars of Eternity - you also require supplies to rest, but you can carry only two any any given time. That means devs know you enter with specific amount of rest and can plan accordingly. If dungeon is longer they just drop supplies to find within the dungeon. Of course, if one runs out of supplies nothing stops player from going back to town for more. I found it best, because it doesn’t put pressure in players deciding how much supplies they need, and it clearly communicates suggested pace of resting. Still, more or less skilled players can rest less or more without setback.
As someone mentioned, BG3 ties narrative content to resting, so whenever BG3 should discourage resting at all is another matter. But I don’t see long rest problem being fully solved without shaking up structure. Rogue-lite could work well (Darkest Dungeon comes to mind, we’re supplies need to be taken, players get information and experience needed to make an informed decision on how much supplies they want to take, and miscalculation results in consequences while the campaign continues (be it retreat or death) instead of reload).
