Here's a question: does either version of WotC 5e actually say anywhere in the books that the game is designed around attrition, and that ignoring this is working against that design? It that made clear in the text? I think it's possible a lot of folks just see "heroic fantasy adventure" and stop there, with little attention paid to, "manage your resources or the math stops working properly".
As you well know the text (2014) recommands 6-8 moderate to hard encounters for an "adventuring day", i.e. between long rests, with two suggested short rests. The use of limited features is balanced around this idea.
With many features short or long rest, as opposed to at-will, this leads to the players having to judge when it is best to utilize a limited feature. Going nova all the time and during the first encounters then naturally leads to a dought at the end of the day--times when you might wish you had the "extra fuel in the tank", on occasion.
It isn't an issue of managing your resources so the maths works, it is a real-world game issue of wasting resources needlessly or thoughlessly.
Consider Action Surge. With 7 encounters between long rests and two short rests, a fighter is balanced around the idea of using action surge roughly every other encounter.
Compared to Rage. With 2 and later more, it starts out rage is limited to about 1 in 3 encounters, and near the end you can expect to use it almost with every encounter.
What about Smites. You begin with (at most) 2, if you don't cast any spells. Like rage, about 1 in 3. However, by the end you will probably have 10-15 depend on spellcasting, so you can count on probably 1 or maybe 2 per encounter.
The relative strength of features is balanced around their understand of their use and how often they should be able to employ them before a long rest. When you ignore that, and allow more fequent rests, the classes which require those rests (and tend to have more powerful features because, in theory, they should be limited) feel more powerful because those features aren't limited now.
I mean, come on, you know all this. Why bother asking?