There are very few individually maintained OSS projects that would generate enough money from donations.

Henry Zhu, who maintains the massively popular Babel transpiler, only gets $2200/month in donations

https://www.patreon.com/henryzhu

I agree with your main point that OSS is underfunded, but Babel also collects donations through Open Collective[1] and Henry Zhu withdraws a monthly maintenance fee (recently $8k/mo).

[1]: https://opencollective.com/babel

At least there's clear progress. Things like Patreon are great for reach and engagement. It's a step-up from having to either work at a company directly using the tech, or keeping it as a "side-project" that either eats your life away or lags behind.

projects don't get donations just by existing and being used. They need to actively acquire donors/patrons just like businesses acquire customers. Asking for patrons for an individual is also a whole different thing from asking for patrons for a project.