Stepping away from the details, here is what I see this as.
5e has a "hest" design - thinking old school style tech - where you start with abilities to use and as you use them you gain an increasing problem that needs passive effort to clear. So, inactivity is needed to reload or refresh your abilities.
Thats "big picture" - obviously it's more complicated since z lot need long rests, some need short, dome keep going but are kinda middling.
What is being described here us actually more of an "ammo" approach where the keys to using your abilities are active efforts, getting CPU to level up.
But, really, frankly, resting is actually evdn more sn non-fiction thing than levrl up is, most of the time.
So, frankly, 5e is not built to work this way. In my opinion tho, an rpg could be abd it could be very unteresting.
Imagine if each PC was built with a few potent resource demanding abilities - a good number of frequent use passive recovery "rest" recharge abilities and a number of unlimited use abilities. Each class or race or background might provide each different ways to get the "fuel" or "Ammo" etc. Each ability might require different fuel.
Obviously, this puts the "recovery power" into the setting in actual action oriented means which also puts it into more GM vonttol, but it's done through a very clear in-game element- less malleable than resting, less meta than leveling.
Perhaps the dedign could put the "fuel" info in the sub-class.
But a game with a design of easy at-will performance at adventurer, limited byt frequent use at heroic outputs and the real top power stuff is one you need to hunt down and actively fuel would be very viable.
Its actually, if you look at it, not that different from many heroic myths and styles ehere the strong hero does good agsinst minions, gets pushed aside by powerful big bad then hunts for added umphh (items, training, weakness into, rtc) to come back and drop the baddie.
So, yo me, switching from long rest to leveling for reload is possibly a step in the direction, but on the wrong road. It should aim at providing an in-game non-meta resource.
That ssid, I dont see the 5mwd as an issue. As GM I provide a mix of circumstances and demands so sometimes its short workdays, sometimes it's not and since it's not always evident which, it's not a problem.