What about pinephone?
I think people often forget federation is not a new thing, it’s a first design for internet communication services. Email, which is predating the Internet, is also federated network and most popular widely adopted of them all modes of Internet communication. It also had spam issues and there where many solutions for that case.
The one I liked the most was hashcash, since it requires not trust. It’s the first proof-of-work system and it was an inspiration to blockchains.
Using apps that cant provide anonymity and at the same time not the ones that do is very dangerous for society as a whole. Some journalist and activist need anonymity and if only place where they can be heard is on mainstream apps that don’t offer anonymity, they are stuck.
Email is federated as well, but I never saw anything I could call email instance wars. You can use whichever you want, no one really cares.
I don’t know too much about lemmy yet, but all of these things (tagline,siudebar and legal info) sound like they should be controlled only by admins, that should be able to add html code anyway (since it their website).