Think about classical music. We all know about Bach, Beethoven, and Mozart. They broke molds and people after emulated/were influenced by them. And while there are plenty of classical composers since then, only those who really study the genre will probably know their names by heart.

So it'll probably be with the future of pop/rock music. Plenty of amazing artists then and now. But the majority of future generations will only know the names of the influential giants. The rest will have to dig deeper.