@realn2s@OSCo It's been 7 years since I wrote about #OpenCollective. I haven't used it myself, but it seems to have grown healthily. At https://opencollective.com/ you'll see that it's not restricted to the U.S.; there are currently 15,000 groups around the world who raised & managed $35M last year.
For tips and learning on participant-driven and participation-rich meetings, there is a wealth of information on my blog (800+ posts) and in my 3 meeting design ebooks ($49.99 for all 3; $19.99 each).