I would be surprised if they even get a thank you per 1,000 users.
I advise you to go read the Road and Bridges report i linked in the blogpost.
As of today, the reality is not at all. As I mentioned elsewhere there are zero maintainer of autoconf since 2012, even less one well paid.
Log4j devs took unpaid time off to fix it.
OpenSSL dev lived for years with less than 10k per year.
I suspect many people working on OSS are getting paid, if not handsomely, then enough to survive.