And that’s objectively worse for the game.
A big part of this game’s appeal is its customizability through addons, and the vast majority of addons that are too powerful (that thing from Wrath, the range radar, WAs being attached to nameplates, etc.) have been addressed and fights have become much less complex on that front since HFC. A lot of complexity from fights comes from needing spreadsheets, and that stuff can’t even be fully done in-game either.
A huge number of people can and will quit if you start breaking addons on a large scale like this, because you and I both know that Blizzard will not meet folks halfway and make better telegraphs for mechanics if they end up breaking boss mods overnight, nor will they magically make bosses easier after breaking addons. Archimonde was extremely hard for his time and was the biggest example of addons getting too complex for their own good, but just because they broke Archimonde doesn’t mean fights became easier. Mythic KJ, Mythic Uu’nat, Mythic Halondrus (pre-Tuesday’s nerfs), Mythic Jailer, etc. were/are all extremely hard bosses, and in KJ’s and the two latter’s cases addons don’t come close to trivializing the fight considering they’re all notorious for “one mistake = an instant wipe, period.” Even Uu’nat, as an addon fight, was still a fight that guilds realistically weren’t even capable of getting to because the fight right before him was just obscenely hard, addons be damned, and addons didn’t even play the game for people on that fight because he was considered the hardest WoW boss of all time even with addons being used.