My "fallen out of love " band would be Oasis. Loved them back in the day. These days I rarely listen to them. I still think they are great musicians. But their music doesn't do much for me these days.
So I hated them back in the day but finding now that I really love their two fuzzy monsters (Morning Glory and Supersonic) - I reckon both of those songs are terrific. A lot of the rest of it I find pretty meh but those two songs are huge.