Problem is the 4e defense doesn't really make all stats important, in fact, it does the opposite. Based on class, a few stats really matter, the rest don't. I dont think 5E went far enough making all stats matter to all characters.
Well no. It makes them closer to being equally important when building your character, but obviously not in play. And even then, you ran into issues-
Str gives you carry capacity. Con gives you healing surges and a few more hit points.
Dex gives you initiative. Int does not.
Cha gives you social skills. Wis gives you...Perception and Insight.
But I don't think any edition has ever managed to make all 6 ability scores equally viable. I mean, when I started playing in AD&D, Charisma didn't really do a lot by itself. Sure, it came up more at level 9 and up, when you're doing the base building thing (IF your game was doing that), and presumably it would matter if people were using the NPC reaction rules (which I never saw anyone use, but that's my own experience).
And it really hasn't gotten much better, other than, now there's incentive to have high Charisma for a few classes (technically Paladins and 2e Bards wanted Charisma, as well as a couple of specialty Wizards, but that was just a prerequisite, it didn't actually fuel any features).
Proficiency bonus matters more than ability bonuses even now, so it doesn't take much to be a face other than proficiency in Persuasion (and there's a few ways to get expertise on top of it).
To truly make all six ability scores equally useful, the game would have to use derived secondary characteristics, which is a layer of complexity I don't think the majority of D&D players want.
