This mythology surrounding the suffering artist is pretty much a fairly modern invention. That's not to say that earlier artists didn't struggle - but it was not fetishished in the same way.

Mozart, Handel both had wealthy patrons, and made music for their use. Mozart also made quite a lot of fairly commercial music. Bach and Teleman both worked for the church.

Was Rembrandt a worse painter than Van Gogh, since he had wealthy patrons?