That’s a tough hill to climb. The internet grew on the largesse of individuals who contributed time and financial support to smaller endeavors, whether it be software or a website. It’s going to be all but impossible to get people to pay for it when even big services like Facebook are free, that’s the conundrum and why ad revenue and personal profile mining is used to fill the hole. Unfortunately costs have risen sharply alongside bandwidth demands, so one can’t run a basement server without bottlenecking on size or costs long before reaching critical mass for a community - and that’s what you mentioned in regards to lemmy.
Like I said…above my pay grade. I hope there’s some way a distributed network like Lemmy can succeed, I really enjoy what it’s becoming. Maybe a hub-and-spoke system will be the final form…big instances supported by more commercial means and smaller instances run by individuals and private funds.