You wouldn't think somebody like U2's Bono would admit to how crappy he thought his singing sounded, especially from the earlier days of the band's fame, but he talked recently about hearing a U2 song coming on in a car and saying "I'm just embarrassed. And yeah, I do think U2 pushes the boat out on embarrassment quite a lot." Bono's not the only one who thought his singing wasn't great--the late Robert Palmer (Addicted to Love, Bad Case of Loving You) in a conversation he had with U2 bassist Adam Clayton, thought Bono was straining to sing too high, and asked Clayton if he ever told Bono to sing in a lower key, adding, "he'd do us all a favor who have to listen to him."
Oh, by the way, Bono says both he and guitarist the Edge never liked the name U2,....get more on all this, and why they went with the name U2 anyway, here: https://ultimateclassicrock.com/bono-embarrassed-vocals-u2-boy/