This is a thing actually on Breaker and Stitcher. The show I host offers this as a "premium feed."

Not a ton of interest, unsurprisingly, as most people don't experience enough inconvenience in an ad to shell out.

Some do this. The Savage Lovecast, for instance, has a subscriber-only feed that delivers the podcast with no ads and more content.

Are the ads really so bad? they're skippable quite easily if you are really annoyed.