I believe the disconnect is here:

An RSS feed is typically hosted in a single location. To nostriches this is centralized.

To the Podcasters, you self-host your RSS feed so it doesn't matter that it's centralized to yourself.

The RSS ecosystem is interoperable and that's the sauce. Centralization is only a concern if you upload your feeds to a third party service (analagous to having a custodial wallet). If this concerns you and you don't want to serve your own files from home, utilize nostr blossom relays (or something like that) to host your RSS feeds and now youve got best of both worlds.

Don't recreate the wheel. But we can improve a few things along the way.