There’s plenty of mediocre musicians who became world-famous, and plenty of great musicians who nobody’s heard about. Skill and success are pretty weakly correlated.
This is a fun and complicated topic. Yes, sometimes things outside of the music influence our perceptions of the music. If the Red Hot Chili Peppers were a bunch of bald fat dudes maybe they would have had less fans; if Kurt Cobain hadn't killed himself he would still be a legend but perhaps in the calbire of Eddie Vedder and not what he became. But the following underlying principal I believe to be true : it's impossible to survive the test of time in music without producing "good" music. Example of music that survived the test of time : The Beatles, Queen, Pink Floyd and I'd argue Nirvana, Pearl Jam etc. How do I define "survive the test of time" is another discussion I'd rather not get into lol.