Two examples, off the top of my head:
1) Here's how Open Collective looks, for jMonkeyEngine (a lovely Java game engine that's also a bit underfunded and underutilized): https://opencollective.com/jmonkeyengine
2) Also, here's the Patreon of Godot (a more hyped and better funded engine): https://www.patreon.com/godotengine
Why would large enterprises not just use a tool like that, if they already use the likes of AWS or other IaaS/PaaS/SaaS offerings?
But i definitely agree that a lot of open source is underfunded and as a consequence many can't work on it full time or even every day, because things are dire financially otherwise: https://staltz.com/software-below-the-poverty-line.html
Not everyone has cushy jobs that make them $100k a year, i make closer to $21k in Europe now, about which i wrote on my blog: https://blog.kronis.dev/articles/on-finances-and-savings
It feels to me that perhaps the solution here is to have something like a bot on GitHub/GitLab, that adds a comment to issues: "If you'd like to express to the maintainers how important this issue is and draw more attention to it, then submit a payment here: ... Payments so far: ... (possibly with messages by supporters)"
Most people don't care about Open Collective or GitHub Sponsors or whatever, they just want to make feature requests or bug reports. If their attention is captured and the ability to make their own request/report more visible is offered to them as a part of that process, maybe things would be a bit better? I've definitely heard the sentiment expressed that micropayments have the potential to improve how we interact with others on the web in some ways, i'm just not sure how viable that is.