There's a system for creating monsters lol.
I never claimed anything about playtested that's another poster.
I'm not claiming anything about quality either but it's verifiably false that 5 E has more options than 2E.
You might like 5E better but once again that's irrelevant.
The gritty rules in 5E don't actually make the game gritty.
It only changes how long long rests and short rests take. It changes the pacing of the game in terms of in game time
It doesn't change the actual wayvtge game runs or expected encounters.
It just slows down the level 1-20 thing game year you can pull off.
Compare with say the historical ha books where all magic is ritual magic and high level spells don't exist.1-3 points if healing a day and clw is a miracle.
Could you modify 2E to be that "gritty"? Sure. No game I ever played was. I don't remember any of the options you mention in any books published by TSR, but that doesn't mean much. When has all magic ever been ritual magic? In what (official) version of the game were there no high level spells?
While TSR published a ton of stuff and I'm sure I didn't keep up with it all what you describe seems to be either home brew or 3rd party.
But I don't think it would be any more difficult to make 5E just as gritty and there are plenty of options available in the Dms Guild if you don't want to take half an hour to come up with some house rules. Even just using all the "gritty option" rules from the DMG makes it more difficult for casters to recover spells while still being extremely limiting on natural healing.
I can't think of anything else to add that doesn't just come across as snark.