I think the question is: is AntennaPod better? Or did you switch because it was open-source and good enough?

Open source and without tracking. That is better than good enough.

https://github.com/Automattic/pocket-casts-android/issues/42...

With Pocket Casts' release as open-source, this now applies to both, so I am asking whether this was the only deciding factor back then.

I've been using AntennaPod for years, my question is, is there any reason to switch to Pocket Casts? Aside from the sync-feature which seems nice. Everything else in the feature-list seems available in AntennaPod as well.

I don’t know if AntennaPod has it, but with syncing you also get a desktop (macOS/Windows/web) app. I use this to I listen while work, and switch to my phone at other times.