I’m not overly worried. There are plenty of Mastodon servers out there that have been running happily for years on donations. The running costs, while I’m sure aren’t insignificant, are also nowhere near what it takes for somewhere like Reddit.

The good thing with the Fediverse is that the more users it attracts, the more servers spring up to accomodate. That’s kind of the whole point, to balance the load between servers rather than have everyone on the same one.