This is a common perception a lot of men have, which also leads to incelness. That average, whether in looks, personality, body, status, is “good enough”.
But just use logic for a second. Being average in a sea of people doesn’t make anyone stand out or become appealing. They just seem bland. Only those significantly above average will even get a chance. This applies to everything in life. Jobs, spouses, entertainment.
This is why 99% of idols look so different from 99% of Koreans who obviously have their own average look.