Yes, it might be nice to have an "Add to my music" option also in an artist's "three dot button" menu. However, for a more prolific artist, it becomes a bit of a problem, because those artists will also have a lot of best-of albums in their collection, or re-releases/remasters, etc. Also, some albums might not even belong to that artist (they might have ended up on the artist's page by mistake). You might end up adding a lot of stuff to your library that you really don't want.
As an example, I just checked the "Albums" listing for Toto. They have released 14 albums so far, plus one live album, but there are 28 albums listed. The rest are compilations, duplicated items, singles that for some reason appear as albums and stuff from other musicians. I wouldn't want that kind of mess to be added automatically to my library.
So unless Apple decided to human-curate the discography for every single artist in their catalogue, this will not work.