The short answer is it actually get WORSE!
I have an old 5s and figured I'd take the plunge to ios12 for security reasons and kind of regretting it a little.
There's some nicer interface here and there but overall insignificant but somehow the podcast app has regressed.
I have a few that I listen to almost every day and a bunch of others that I'll listen to now and then....sometimes it's a month or more. I do not save any of them to my phone because I have no storage, and one of the podcasts I listen to daily for some reason will show the next up in the cue from 9/11/19, even though I've listened to every episode to 10/4/18.
I just don't understand how they keep making it worse and worse and less intuitive. I find the podcasts flow similar to reading fb's rules, where it like some non-english speaking technoid cobbled together the podcast app's architecture through some translator app-book-bathroom wall or whatever........you'll end up with a turd.