I have believed this precise thing regarding stealth since the beginning. And in fact, with exception of combat, this is how the designers I suspect want/wish all of D&D to go-- building 'first-order' frameworks or foundations for game rules so that all players have a baseline from which to build from... but all the heavy-lifting of rule systems would come from the 'second-order'-- the players themselves, generating applicable rulings in the moment to cover what it is they are doing. Because only they know what they actually want and need to accomplish with their goals in D&D in terms of layering their "storytelling" in and amongst the "game".Which is why we are where we are with stealth: it's basically impossible to write clear rules that will work in all cases, so the designers of 5e decided to basically not write rules so much as a framework for rulings and let it happen at the second-order level.
The thing that I've been hammering away at to everyone here on the boards for years is the idea that in D&D... "creating stories" is more important than the "board game". The actual game rules do not matter if the story of what the characters do is good. So whether there is a lot of rules, or few rules, or indeed even no rules... however it is we generate and create what our characters do, how they behave, and what adventures they go on is what make us play D&D (or any roleplaying game) instead of just playing standard board games (the games that are entirely 'first-order' rules-based.)
Now of course me being that reductive about it just tends to piss everyone off more often than not... but so be it.
Dungeons & Dragons grew out of a "board game" (IE miniature wargaming) by adding in the ability to create original characters, stories and narrative. People determined that while playing the miniatures combat game was fun, they wanted MORE. They wanted to create a character, and run a character, and see where this character went, and find out what this character did. And all of this... this "storytelling" (or "roleplaying" as it were)... was not something you could not create strictly with game rules. You needed to use your own imagination and create these things on your own apart from the game rules. You had to decide to turn left at the dungeon fork and then pull the lever you saw on the wall... there was no die roll or rule in a book to force you or tell you to do that.
Now the miniatures combat game rules could facilitate this "storytelling" by giving us a first-order foundation of possible actions we could take and from which our stories could build on top of... but they couldn't tell us everything. And even today with skills, and feats and this and that... they are there again as merely a foundation of ideas that we players can start with, but which we will have to build upon ourselves to encompass all the possible ideas we will think of to do. And because it is impossible to have 'first-order' rules for all those things... we HAVE to move to 'second-order' rulings to cover the gaps. And how successful we are with the second-order rulings depends on how solid the first-order foundation is.
So the question becomes... how many 'first-order' rules are necessary to give us a strong and solid foundation from which we can generate our own 'second-order' rulings that accomplish the storytelling we want? In the case of stealth for example... since almost every single table ends up wanting the stories that come out of sneaking around to be different than almost any other... WotC decided that the more basic and narrow a 'first-order' foundation was ... allowed every table more room to expand our 'second-order' ruling to actually reach the narrative and storytelling results we were looking for. More rules only serves those tables for whom those rules actually work... everybody else has to tear down those rules first before then re-building them in the way they want the rules to go. And this lesson can be taken across the board with every rule in the game.
The only reason to have more 'first-order' rules would be to widen the foundation from which people could build more and different 'second-order' rulings in order to create more and different stories for their characters. And how necessary those are really comes down to how comfortable and how willing people are to make those 'second-order' rulings. If they aren't comfortable doing it... they want more 'first-order' rules to do it for them instead. But at some point... a game of nothing but 'first-order' rules IS just a board game and not a roleplaying game at all.