On the Fireside Fedi interview with Jerry ( the admin of Infosec.Exchange Mastodon instance ) a scary truth was suddenly revealed ( on 34:11 ): Just to keep the instance up and running he needs to spend up to $5000 a month, pretty much out of his pocket. Donations to the instance barely cover any of that. And if he will ask people to pay to use it, they will, rightfully so, switch to a different instance.
At this point, you’re better of self-hosting, or even co-lo hosting. Cloud environments are good when you need to scale faster than servers can be shipped (or plan to scale down before the costs add up), but $5k a month is literally a new, decently-beefy server every 2-3 months.
In terms of solving the money issue, I feel like the only solution is a shared-cost/ shared-ownership model, where you get an initial pool of money together for the initial build-out, and then monthly costs are divided equally among all members. You can’t rely on donations, you need collectivism.