I just discovered podverse from browsing f-droid a few days ago, has some similarities with pocket cast which I have been using since before they were sold the first time.

You can also use the news app for nextcloud to show podcasts along with rss news stories, if you are looking for something along those lines.

I actually just submitted the podverse link for discussion here just a few mins ago, so I am pasting a link:

https://news.ycombinator.com/item?id=32922268