Let me just reach into my backpack and pull out one of mana potions of this stack of 99 of them, and spam the chug button (drinking several gallons of liquid) to get up to full mana, hmm sweet sweet verisimilitude.
If mana potions are that plentiful then why are we bothering with resource based abilities at all?
This kind of cynicism undermines itself when it fails to think more than a step ahead.
Well, people need to rest, and needing to rest to recover stuff makes sense.
No one said resting can't still be a thing, just not the thing.
People need to remember this is still a game, and rests do not (and haven't) made for a better game. In a high fantasy world like we see in most DND settings, potions restoring someone to fighting shape isn't violating anything.
Not being able to rest if you're not in a town, or never being in danger no matter what if you're resting, does.
It sounds like you are saying that Diablo potions would be the primary way people recover hit points, spells, and rechargeable abilities.
My idea is you have Mana/Stamina up to some number, and all your abilities cost some amount of this. There is no "recovering" of the abilities themselves, only your energy.
The idea that abilities just shut off and can't be used again isn't bad in some cases (daily powers make sense, for ex), but applied unilaterally across all abilities is just contrived.
That said, well first of all I agree with everyone else who said chugging mana potions isn't their idea of better verisimilitude*. Second to that, if you are going to readdress the rest/recharge system, readress the fundamental assumption that underpin it and/or proceed from it:
*where does the big bad NPC who lives in the aban
In an ideal system, potions would be a last resort to keep fighting. Slow natural recovery works in the interim.
As said above, part of the issue it seems some are missing is that doing this means abandoning the notion of spells and abilities and all that being the things that get recovered. Energy is what gets recovered, and players spend it as they please.
Something that I just simply cannot comprehend is why people who likes 4E is spending all their time trying to "fix" 5E into being more like 4E. Why not just play 4E? My group went back to 2E during 4E for pretty much this exact reason.
5e is 4e. Its not a coincidence people keep reinventing 4e, because they're just falling into the gaping holes that were dug into 5e to hide what it was.