Yeah, house rules like "sanctuary resting" and "gritty realism" are common responses to the problem. They work for some people.

They do not work for people who want to actually use their cool powers.

Like, if your group enjoys the resource management part of the game? Great. These can help. In my experience, most players do not.

Like let's say a mid level party encounters a group of goblins. Let's say the players see the goblins before they're detected.

A lot of players are going to want to go "fireball!" and try to take them all out at once. Because that's pretty cool, right? But if you're playing with resource management in mind you have to think about if that's really the optimal move. If you can sneak past without a fight at all, that's better. Spends no resources. If you can do it with a lower level slot like invisibility, that's also better. Save the fireball for a threat that can't be dealt with with less. Hell, if you can come up with a good strategy to just take them out with tactics and minimal damage, that's probably better, too.

But most players don't want to play that kind of strategic thinking. Frankly, most people aren't especially smart, and they're not firing at 100% when they're playing a game for fun.

So the players just want to do their cool powers, but the game's design is still anchored to "make them count because you might need them later"

If you limit long rests you can help address the problem of the characters having too many resources, but it doesn't really address the problem that players want to do cool shit. Players want to fireball more, not less

But you can't really fix this in DND without doing a lot of rules changing. A lot a lot.

And this is one part of why DND kind of sucks. There's not really a way around it.