a semi-related opinion that I don’t want to clutter that thread with: self-hosting is awful* and there’s a big opportunity to develop structures for community-hosting things like git forges, chat servers, &c. Spread the load and develop social experience for sharing resources *: too much work for too little use, too expensive, nobody wants to be on the hook all the time for maintenance so it rots

The problem is partly that nobody understands the cost and efficiency characteristics of the community software we're all only recently starting to want to share. And we also keep developing new features, so lessons about cost keep getting obsoleted. The ideal for society is not "free" as various idiots proclaimed in the 200x's and 201x's. The ideal is accurate and transparent cost models that are decoupled from a profit motive. Right now the only people able to reliably bill for usage are AWS and equivalents who also have an interest in maximizing what they bill. And so what seem like non profit-motivated groups fail either by miscalculating costs and going bust or turning out to be (or become) cost predators in what was originally sheep's clothing. In all this I'm assuming "maximize profit" is a terrible motive. Unimaginative and cringe for one -- you could aim so much higher! -- and leading to huge externalities for everyone else.

There are maker spaces which already manage sharing community resources via a monthly donation fee. Seems less useful for stuff like git hosting but I can imagine no-one would be against it. There is a somewhat canonical guide to setting such an organization here (for the UK), which would be a bit different with no tools or physical space involved but some of the legal structures remain. I imagine US has one too.

yes, I think a Maker space is a good model - a digital maker space

In line with @Kartik Agaram's comment, I think what we need most right now is people experimenting with the management and governance of digital services. Codeberg is one such experiment: a forge run by an association. If you want to participate in governance, you sign up as a member. social.coop is another such experiment: a Mastodon instance managed and governed by its users. I am sure there are more examples. Both Codeberg and social.coop share the problem that governance participation is too much of a burden for small-scale users. For both forges and social networks, I'd prefer to pay someone I trust, while having the option to move elsewhere if that trust is broken.

cosocial.ca is another example, I agree that both of those models are inspiring, and that moderation is the big reason to prefer a large central server to more smaller ones

I think what you describe above comes close to the LURK people?