Favoriting episodes, bookmarks, auto-queues, prioritizing podcasts, downloading episodes for archival purposes, playback history, list of all episodes in progress, stripping empty audio, crazy amount of configurability, and an interface that isn't terrible. I'm sure there are a bunch of other features I'm forgetting.

I've tried Spotify. It's not a podcast player. It's an audio player with none of the conveniences of a modern podcast player. If all you want to do is listen to podcasts, I'm sure it's fine, but it's not in any way sufficient for my needs. At this point, Podcast Addict is the only app out there that I can stand to use.