I deliberately don't use any of Apple's services, even though I own an iPhone. The only thing I use is the App Store, and even then I'm a minimalist as to what I install. If I want to listen to podcasts, I use the VLC Player app, and grab the podcast from the Podcast's official site, and then use iTunes to transfer the .MP3 to VLC, over USB. Cause I'm oldskool like that. If the podcast in question doesn't have a site…
I appreciate the sentiment of not wanting to give into vendor lock-in for convenience but why manually download podcasts and go through the whole process when you can use RSS and ask podcasters to keep supporting RSS feeds? You get good ergonomics while still keeping the process decentralized and without vendor lock-ins?
I own an iPhone but also don't use Apple's built-in functionality unless the feature supports standards-based services can self-host (CalDAV, IMAP, etc).
I pull podcasts into my forked version of tt-rss[0] and use a script to pull down the enclosures onto my local webserver. I play the episodes using Safari (which, admittedly, is a sub-optimal experience) on my iPhone. (In my dreams I'd write an HTML5 front-end to play episodes, mark them to retain after listening, keep bookmarks, etc...)