Yes and nope.

I don't think it's as simple as "They are worse now than before" - As I could easily pick out other raids and instances where the contrary is true, and even just in general.

I would say though on this note, that a lot of the contributing factor is just simply a lot of the older content after many of the reworks is just not really preparing people as well as it should. e.g., you can go through WoD largely not knowing a damn thing and not have a single wipe or an individual death. e.g., a few people in the party can quite as easily prevent wipe-able and killable mechanics.

You can also attribute this to the fact that ARR alliance raids are now mandatory from a very early stage in the game, where comparatively in the past you could get away with not doing them until Shadowbringers, or equally you could get away with not doing them at all, just prior.

I think you forget just how the average players were in previous expansions.