Well, it was a lot easier to be self-taught in Newton's day... there wasn't that much to learn! You could read Euclid and you're be mostly done. Newton alone probably made learning mathematics at least three times harder during his career.
Anyway, if you're trying to make me regret choosing mathematics as one of my examples, y'all have won. I see no molecular biologists have popped up to advocate for self-taught molecular biology.
I've read that the last Universal mathematicians we've had were Chebyshev and Poincare, who could claim to know "all of math", and who were active in research in nearly every sub-field. It's been over 50 years since their time, and much like the fabled Renaissance Man, that frontier is now closed.
Anyway, if you're trying to make me regret choosing mathematics as one of my examples, y'all have won. I see no molecular biologists have popped up to advocate for self-taught molecular biology.