It does. You're just ignoring it.
No, there's a few connected issues going on. One is the disparity between short-rest and long-rest resource classes. Another is the players constantly pushing against those limitation. Another is players constantly trying to nova and long rest after each and every combat. Epic heroism and cranking up the difficulty solves all of those in one go.
In the DMG the designers flat out state what their assumed daily progress would be. Long rest, 1-2 combats, short rest, 1-2 combats, short rest, 1-2 combats, long rest. If you limit short rests to no more than two per long rest (as the designers stated in one of the books, Xanathar's I think), the resource disparity is solved...as long as the players don't nova and push for a long rest. Which they always...always...always will. So you need to also either artificially enforce a set number of fights between rests...or condense the "adventuring day" with epic heroism, thus sidestepping that problem entirely.
If you don't like the solution, cool. Don't use it. But it's still a solution.
No solution will ever be perfect, so if your response is "but it's not perfect" well, I don't know what to tell you. Nothing ever is. It's worth noting that 4E doesn't have this problem at all. If it's a major concern for you, try 4E.