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.
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).