Truly an unpopular opinion lol. Like others have said, I would gladly setup a recurring donation to sustain my instance. From what I've read, most instances are relatively low cost as long as their user count remains small.

Another thing I'd be willing to do is pay a small monthly fee to host an instance on a server somewhere. I'd restrict the user count to ensure the cost to host remains low.

I'd prefer both of those options over ads. It's unnecessary considering the entire idea of the fediverse is to spread out users across many small instances instead of having some huge costly monolithic instance.