So why did I stop using Tumblr? Back when I stopped actively using it (I still have the account), there were two main problems. Firstly it was utterly broken in varying but always original ways. It gave me the impression that people working for Tumblr didn't use their own software. Secondly they introduced terms at the time (when they were under Yahoo) that forced you to accept that everything you did was communicated to all kinds of 'partners' like Facebook, with no opt-out. The latter has since relaxed.

This caused me to look into Mastodon (at first) and I've since started to appreciate the open source nature and the ability to have different servers with different moderation that all interoperate.