Actually, I think their lyrical peak was Joshua Tree (which I rate slightly over AB because of the tightness of the songs). Although One is their finest for lyrics yet.
But, Yahweh on HTDAAB was solid, lyrically, imo. So, too, crumbs from your table.
Nevertheless, I think you are correct that their lyrics haven't been spectacular of late. It all depends on what one is looking for in a lyric. Some songs can be simplistic yet powerful. Beautiful Day is a favorite of mine and because it both connects with things in my life and it lifts me up on days I'm really down.
There is no absolute standard on lyrics, it's all about where one is, how one is touched, and what one enjoys. At certain times the light hearted is better than the heavy.