You keep using this word "musician" but I believe the term you mean to use is "recording artist."

That's that person you go see at shows, like you know, famous rappers and pop stars and rock stars.

These are professional entertainers.

Beethoven was a musician. So is Aphex Twin. So is a guitar player in a bar cover band. Each have a work output that take very different forms.

Many musicians are composers whose work ONLY exists as a recording.

I don't know how it is possible for you to hold such strong opinions about this topic without understanding these concepts.