All those federated platform will only become popular if the backend is dumb and the frontend is smart, i.e. you create your account on a frontend but can use the same credentials to connect via another frontend and no matter which frontend you connect to, all content for the platform is accessible to you, there's no admin having control over your experience, only people offering different UI experiences. Federation/defederation/deciding to host NSFW content, that's all taken care of behind the scene just like on Reddit, for the user they're just using Lemmy via frontend X or Y and they decide what communities and users they want to block.