Use the revolutionary Open Podcast index https://podcastindex.org/
Live and functional now
Created and curated by the podfather himself Adam Curry with Dave Jones
You probably already know about it.
Podcast Addict has been using its own podcast repository for the past 9 years. Sorry but this will not change
I understand, I've just noticed that I still have to hunt for RSSs sometimes. Those guys were instrumental back in the dawn of podcasting and are still working on creating open source standards. It's still in development too, just something on the horizon.