M+ never lost its identity. All content has has constant change, evolution, and upgrades.
For example with uncapped AoE in Legion, you could trivialize some mob packs by just death balling them and AoE stun or stop. Barely anyone interrupted, it was a waste of a button push.
At the start of M+, you could also 3 chest and get more gear. Yes, the community liked both aspects, but there were groups that couldn’t handle it, the people that liked the PvE side of the game, but might not have 2 hours to set aside for raiding. Maybe they only have a half hour, or an hour. If you ran with pugs, and they weren’t going to get 3 chests, you had lesvers, destroying your key.
So daddy Blizzard changed it. This meant you had less leavers. Still had that uncapped AoE, but they changed that going into the next season.
Are you just annoyed we don’t have Legion M+? Or was new and needed iteration. That’s just a fact. You also need to remember that canonically, that was when our characters were at their strongest. Some Artifacts could destroy planets (like destro warlock’s). We used all that power to make sure our World Soul didn’t bleed out. The consequences of that led to BFA.
M+ its supposed to be an end game pillar. Making choices, positioning, and finding out our solidifying what you can handle is perfectly fine and reasonable. Blizzard made changes to M+ for everyone. But no pillar of end game is supposed to just be easy. It’s supposed to challenge you, and you are rewarded based on the risk you took.
Again, M+ will change. Raiding was in other MMOs before WoW, and ran alongside it. PvP’s BG’s got expanded into Rated and Arena. Those didn’t happen over might. M+ will find its niche.
Will I defend everything? No. But with more limited AoE, can that AoE also be more potent against that smaller pack? Ye.