Lemmy will die out without monotization such as every 6th post being an ad.
I love it but feel like libre projects that have constant maintenance costs beyond developers’ time need to find ways to become mostly self sustainable without relying on donations. I also dont mind less than 20% of the posts being ads.
Im not sure what are its income resources, but never the less - mastadon is still quite a niche site. Not nearly as big as reddit or X.