There are definitely counter-examples. Linux wasn't started because Torvalds thought it would get him rich quick. Rowling didn't write the first Harry Potter thinking it would eventually earn billions. Plenty of famous artists, inventors, and scientists died poor, only receiving posthumous recognition. Key vaccine researchers were resigned to struggling in less-profitable sectors of biotech until 2020 happened.[0][1]

People in a great many fields put in huge amounts of effort for very little financial reward (and even virtually guaranteed hardship), and sometimes that results in huge benefits for the world.

[0] https://news.ycombinator.com/item?id=26125003

[1] https://www.nytimes.com/2020/04/27/world/europe/coronavirus-...