Within 100 years, an entertainer will probably be completely forgotten. Can you name any famous entertainers from 1904? See what I mean? There are a few exceptions, but they are very rare and their fame almost always got associated with someone or something else to endure.
No matter how shocked we are that people who got such wild fame are being forgotten, it's normal. Records of Old entertainment are simply not preserved well and are replaced by modern entertainment.
Old entertainment is shown less and less as time goes on. Abbott & Costello films used to be shown on Sunday morning TV when I was a kid. Now try to find one of their films playing on any of the hundreds of cable channels you might get. Marx Brothers films used to be played often too. When was the last time you saw one on TV?
It's a little sad, but the lesson to be learned is that entertainment fame is not eternal. Unless you make history, you probably won't be remembered. This means political or scientific fame usually. Even then, there's no guarantee.