Thanks for elaborating on it, it’s good to learn. The trope though is more about the Enlightenment, Scientific Revolution and Royal Society era. But yeah they were never actual nobility, just upper-middle class. And indeed during the Renaissance and early modern period it was much more about patronage. A number of Greek philosophers were also wealthy, although others were simply frugal.

Nevertheless, my general point stands in that their research was almost never their job and they needed other means to support themselves, just like artists. And this was true throughout history until the paradigm shift described in OP’s article.