In a nutshell, the dnd encounter model is backwards.
The model should assume that a party is at 100% juice for every encounter. And the system should be designed so that abilities mostly reset per encounter. 4e did it right in that regard.
And then....attrition is a function of the encounter itself. Take the mummy for example. You get cursed, and now you can't heal. Oh no...suddenly hp attrition goes from a non-factor into a major deal. Aka attrition should be the spice a DM can throw in, they can set an encounter with the idea "ok today I want my players sweating about hp over the day", and they can add in encounter elements that create those attrition effects. But the core game should assume minimal attrition, because that is the only way to balance the game for 1 fight a day or 10 fights a day. Make that the core....and give the DM the tools to add in attrition when they want that to be a factor in their encounters.
The model should assume that a party is at 100% juice for every encounter. And the system should be designed so that abilities mostly reset per encounter. 4e did it right in that regard.
And then....attrition is a function of the encounter itself. Take the mummy for example. You get cursed, and now you can't heal. Oh no...suddenly hp attrition goes from a non-factor into a major deal. Aka attrition should be the spice a DM can throw in, they can set an encounter with the idea "ok today I want my players sweating about hp over the day", and they can add in encounter elements that create those attrition effects. But the core game should assume minimal attrition, because that is the only way to balance the game for 1 fight a day or 10 fights a day. Make that the core....and give the DM the tools to add in attrition when they want that to be a factor in their encounters.