Universal Healthcare would increase the pool of willing developers by an order of magnitude here.
I'm not so sure. The problem is not a lack of developers. The problem is a lack of developers interested in working on rsync, or on any other specific project you can name. Most developers would rather work on their own projects.
I would also question whether or not universal healthcare (though unquestionably a good thing) would actually result in such an increase in available developers. The following study looked at the geographical distribution of OSS developers in 2021, via Github contributions, and found that the US had a similar number of OSS developers per capita compared to similar countries that do have universal healthcare (see table 2):
https://www.sciencedirect.com/science/article/pii/S0040162522000105