Except it's targeted to whomever I feel like sponsoring. Maybe an additional way could be distribution of a general sponsorship fund based on the number of stars or another measure of merit/popularity? I've sponsored individual projects on GitHub before, but would prefer this way.

Yes, that's my point. It's another market, and while markets have a lot of utility they also tend towards bimodal distributions which disproportionately reward a very successful and visible participants while disproportionately exploiting a much larger group. A pure market system has higher entropy than one which features some redistribution.

https://arxiv.org/pdf/cond-mat/0001432.pdf

I think in France we had some interesting propositions for press funding based on this idea.

Everyone paid a tax each year and gets token that they can attribute to the media they want. The fund are redistributed according to the tokens.

I don't really like the idea of an automated measurement of merit / popularity. Let users decide and choose few projects they want to sponsor each year. Maybe show the current number of sponsor so big projects don't get all the votes.

If something like this is going to be based on number of stars, imagine how this will turn the current "give us a star on github" to.

a game just like amazon reviews. if there's a system that can generate money that is able to be gamed, it will be. star ratings on git hub will become next to useless as it will no longer be used for anything other than monetization.