Many of the most famous and successful open source projects were developed or maintained long-term by paid staff. The Linux kernel is largely developed by paid developers (Intel, Red Hat, etc.). Red Hat employs a large number of the glibc, gcc, X.org, Wayland, and GNOME developers. Rust started in Mozilla (even though it became independent since then). LLVM was developed at University of Illinois at Urbana–Champaign and then was further developed by Apple (and now many companies). LibreOffice started as StarOffice by Star Division, was then bought by Sun and open sourced.
This ‘work for free’ attitude is a pipe dream for companies who only want to benefit from open source and not contribute back. But in the end everyone needs to eat, rent/buy a house, travel, see the world, go out. There is nothing wrong with open source as a hobby, but there is also nothing wrong at all with receiving compensation as one of the motivators. I’d rather see good compensation for developing open source, so that smart people write great open source software, than have them write proprietary software.
Back on-topic. I think there is a lot of less interesting work, were I think it would be great if we could pay people to do it. There was a fundraiser to get better error messages in Nix – not the most exciting work to do, but it benefits the community hugely. macOS support is often lagging behind, because we do not have a lot of maintainers on macOS, so it’s great that @domenkozar and others raised money, so that someone can be paid now to improve macOS support. There are some other areas where I think funding someone for several hours per week would be very beneficial (e.g. triaging CVEs).