Vim. Emacs. VS Code. Log4J. Java. Python. iOS. Android OS. Firefox. Chromium. Safari. There’s quite the precedent for free in the software development sphere.
VS Code, iOS, Android OS, Chromium, Safari all had huge backing and there are huge profit based reasons to make all of them. These should not be brought up at all.
Vim, Emacs, Java, Python: these are huge things. As a creator or high level contributor, your resume is set. Many of the creators of these and others have specific titles at Google getting paid well. Creating such big projects also allows you to get paid tens of thousands for speaking gigs or similar things. I believe it is the jquery creator who was making $500K+ a year doing speaking gigs.
None of these are like Wordle. It isn’t a huge coding achievement that will garner the same financial benefits every thing listed gives.
I didn’t follow the log4j thing but I’d expect the creator to have been able to get lucrative consulting and contracting work beyond what would normally be possible.