People's fame is measured far more than just the number of hit singles or albums they had.
It is also measured on the impact they had on society as a whole, and how well known they are world wide.
Cliff Richard has had amazing success in the UK, but almost nobody in the USA has heard of him.
Lets suppose for example that Bob Geldolf dies.
If he was to be remembered by just his MUSIC career it consists of a couple of hits with the boomtown rats, and that is about it.
But his overall impact in the world, with Live Aid, charity events, raising awareness of hunger etc makes him a far more famous person than just his pop career.
While I was not a great fan of Michael Jackson he has had a huge impact on the world of music, fashion, dance and so on, and is known all over the world.
p.s. I was surprised you did not mention the Beatles in your original list.