It seems that for a large Lemmy instance to be sustainabile long term (especially at the level of traffic reddit sees) it requires ads and/or raising enough donations like Wikipedia
Having said that, is it really the end of the world if large Lemmy instances have ads to make up for any shortfall in donations? Otherwise, how are large instances expected to be sustainable long term, especially if they're going to ever reach the kinds of traffic Reddit sees?
It's good that this discussion keeps coming up; federated instances are not meant to get so large. Once communities become too large they lose cohesion and culture, invariably they eventually sacrifice users' well-being for practical purposes like funding, and at that point they become no better than the platforms they replaced. The cycle of exploitation continues.
There are communities online that have preserved their community culture and have not resorted to unethical practices to maintain themselves for more than 20 years, they are always smaller more intentional communities that value quality interactions over quantity of users. Given all the evidence showing how mentally and socially harmful large centralized platforms are - should we really aspire to recreate those unhealthy spaces in the fediverse?
The fediverse is an opportunity to take things a different direction, a direction in which smaller more cohesive communities share with each other without any one community dominating and suffocating the others. Federation is a fundamentally different model that challenges the centralizing paradigm "growth is good".
do we really have evidence that the problems with a lot of mainstream social media has to do with size? there are shitty smaller sites like for example kiwifarms was vile but not very big. And other sites are expansive like linkedin or quora but pretty benign (if boring) AFAIK.
A lot of people who are comfortable with tech have a hard time remembering how unusual that is. We are all clustered together with each other so it becomes normalized. But think of all the facebook, tik tok, reddit, instagram users int he world. Who will run services for them?
It's all well and good for us nerdy types to say "OK, one out of every few hundred of us is going to run a little server". And we can support that because the % of people who have the skills and resources is extremely high.
For the rest of the population, who is going to put the kind of community cultivation in to setting things up, convincing people to move, orienting users, etc? If this plan was to be viable it would need to have a small army of volunteers to commit to creating instances for specific communities far outside of tech.