The -2% participation hasn't been a thing since Vanilla Naxx.
That said you'd still have a point that raid participation as a whole is a lot less than say, casual content in no small part to the reputation & reality of difficulty.
But without anything to work up to, wouldn't people stop playing entirely outside pvp and m+?
Not saying I'm against the idea, but there would have to be something else to replace it, right? It's not like islands or warfronts did well enough numbers-wise to replace raiding...
... right?