It's a trick question: Lemmy is God.

Identity in the fediverse is tied to a single server (and thus a specific platform) and there is very little interop between platforms even though they're using the same protocol. I have two Bluesky accounts, the one I signed up for and the one I bridged from my Mastodon account. I can't link my Pixelfed account to my Mastodon account. It's kind of a mess.

I feel like a lot of the problems mentioned here could be helped with better identity and content interop between platforms. My Mastodon account should work on Lemmy. I should be able to just crosspost between them without a separate account, or comment on a Lemmy thread from Mastodon, or have #gamedev posts show up on a relevent Lemmy account associated with me.

IDK how viable that is given the way federation works but it does seem like an obvious flaw.

I use both, but only because Old Reddit is slowly dying. Once Old Reddit is dead, the site is dead to me. I can’t handle how New Reddit displays content, how it hides 90+% of the comments and sometimes even the post content itself. I love the brutalist efficiency of Old Reddit, and see the same in Lemmy.