I’d also recommend Gnome Podcasts as the best option. Antenna Pod can export your existing subscriptions as an OPML file and Gnome Podcasts can import that so you can pick up right where you left off.
It doesn’t have a podcast “store” to search unfortunately so to add new podcasts you do need to find the url outside the app and add it directly but other than that it works well and is adapted to mobile.
What other apps were you expecting/are you missing?
You might also find this thread useful, has a few recommendations for flathub apps that work well: