This is such a misrepresentation of the open-source landscape. Yes, there are people working on open-source projects who beg for donations; but there also are open-source projects maintained by full-time employees (Eleventy, paid by Netlify; React, paid by Facebook; Angular, paid by Google; Next.js, paid by Vercel; Linux, paid by various companies; etc.). If a person thinks that his efforts will be better compensated elsewhere, he can always start looking for a paid job.
That's the problem there are no systems in place for it. So if there is no UI for payments on github, people will never stop for a moment to think about what they take for granted.
Nah, nope. You usually don't get the source for proprietary software. Just like you get medical care when you are in an accident, same should apply to work done on os software. Somehow devs should be compensated for their work on os soft.