Or do you think that Sakharov chose to be a physicist because he expected enormous material gains?
No, of course he didn't. He did, however, find himself in Gorky/Nizhny Novgorod against his will.

Does that not constitute suppression?

How was creativity disallowed in the USSR?
Mandelstam paid for a poem with his life; Tsvetaeva was forbidden to publish; Bulgakov had most of his plays suppressed and his best work wasn't published until long after his death. If you want more examples, I'll provide them: there are hundreds, after all.

Taken together, all of these things would seem to serve as a disincentive to unorthodoxy, and, tangentially, creativity.