My own view is that the relative success of the album meant that u2 because they crave success/acceptance so much retreated into (rarely ever to come out of again) being a band making very safe, MOR music......ATYCLB became a template almost for them, a template they became unwilling maybe evem afraid to veer away from.
Trapped in a MOR bubble of their own making of ever diminishing returns.
Yes, it's true that ATYCLB changed the band forever... and for the worse considering I prefer everything that came before.
But I think there's a "moralistic" aspect behind this discussion which is more biased than completely objective, in my opinion. One thing is to critique the quality of their recent output (while understanding that it's subjective, of course), other is this pidgeonholing of U2 as "bold" before ATYCLB and "MOR" after, which I find to be a deceptive narrative, even if instinctively fitting.
There's an excess of focus on the
texture of their sound to describe how "adventurous" is their music, which overlooks all other aspects of craft in their songwriting, and how mainstream it has always been, and how much similirity there is between everything they ever made. After all, U2 is a pop band, and they rarely do anything too crazy or outside the realm of well established influences (usually whataver is "in" at the time).
But when fans enjoy a type of sound and fall in love with the music, they like to inflate it with all kinds of superlative praises like brave, daring, experimental... When they dislike it, it's the opposite. But I rarely see much weight behind any of these claims, including magazine articles which usually just write fluff.
Not that U2 doesn't anger me sometimes with their remarks, lol. It pains me when they say about Zooropa that "the songs were not there"... just sad... which shows how lame can be some of their opinion, usually too much based on public reception.
Nonetheless, while I agree with you that they're too stuck in ATYCLB because it was their last ressurrection after a big scare, I also think they genuinely love the album, and maybe they learned something true about themselves while coming back to that approach... so it makes sense that they chose to follow that route ever since.