For those seeking out a federated and open alternative to Tumblr, Wafrn is looking extremely promising. It can speak both ActivityPub and AT Protocol, offers a ton of interesting features and customization, and focuses on making an incredibly fun experience.
I personally dislike the user/profile centric approach of micro-blogging platforms like mastodon. Platforms like lemmy being based on communities instead is the single reason they are my social media of choice.