I'm an open source author and maintainer of a somewhat-popular python package[0] (~1M downloads/month) that I've maintained for over 10 years. I don't recall ever receiving a donation. I am still maintaining it, but I just don't have time to add the improvements that it needs to keep up with the ecosystem (asyncio, for example). If organizations who use it got together and chipped in some non-negligible amount, I would be much more serious about keeping up with it, but $0, or $5-20/month, is just not realistic incentive to compete with other priorities in my life. I don't know the answer, but that's my thought process.
0. https://github.com/amoffat/sh