At one point, Yesterday was the most covered song (by other artists) in history.
Another interesting point, McCartney didn’t use the band to record it. Just himself and an orchestra. Though he did release it under the Beatles name. After Lennon died, he went ahead and had the records changed to show he was the sole writer of the song.
How could he do that? By legal agreement, all songs either one of them wrote were credited to both until they dissolved the agreement after the Beatles broke up. I looked it up, and it's still credited to both, even though everyone knows one wrote it.