I don't want to sound pessimistic, but I think that only a few percentages of OS projects are worth any kind of money to pay for.

Why? Because who is gonna pay for yet another react select component library that you made. Yes, it's convenient for us to use it, but it's also convenient for you that we use it, because we can also contribute and save each other's time.

I do, though, support the idea of paying maintainers of really big and crucial projects. I'd also love to see companies giving some work time to devs to contribute to OS, instead of being forced to do it in their own time.