Which is fine! The FOSS options are solid.
Personally though, I had tried most Lemmy apps on Android before Sync came out, and found the experience to be lacking. Honestly, I was close to bailing on Lemmy entirely, assuming it just wasn’t for me. Sync was exactly what I needed in terms of UI and organization, and I’m happy to pay the dev for the work they do on it.
I’m on lemmy.zip as well and have been happy. Gravitates towards tech, recently defederated a few extremist instances (by a vote), good uptime, and run by some seemingly cool people.