I’m not sure what you mean about limiting party composition.

Oh I missed this earlier.

So one solution to the pain caused by the adventuring day is to let players rest more often. But some classes get way more powerful after a long rest than others, so that's a problem. A party of {fighter monk wizard} that gets a long rest after every fight is going to have a superstar wizard. One solution to that is only let the party consist of classes on the same rest cadence. Wizard, cleric, paladin, ranger are all long rest based. Fighter, rogue, monk, warlock are short rest.

This causes tension even in a base line game. It's very common for wizard players to whine about wanting a rest even when the rest of the party is good to go. You might say that's their fault for not rationing their powers, but I'd say it's their fault for playing a resource management game when they wanted to play a wizard game.

Removing the adventuring day and corresponding "you need to rest to recover resources" is really difficult in DND. But people want to remove it, even if not consciously, because it sucks unless you're aiming for a narrow range of game modes.