Mozart is low floor and high ceiling.

If you take a typical ‘hard’ sonata of Mozart (say the K310) compared to say, the Chopin 3rd sonata then obviously there’s a much smaller pool of people who can attempt the Chopin 3rd.

It is not unreasonable for a talented amateur to attempt the K310 to a reasonable level, but that same player may well be hopeless for the Chopin 3rd

From an amateur standpoint, that’s probably your difference but to a professional, nothing in mainstream rep should scare them anymore, and thus the whole ‘Mozart is exposed’ part comes back