Cool idea? Yes. Good idea? No. If we do stuff like this, the podcast industry will switch to a closed system which would require you to install proprietary apps to listen to stuff. Likely several different apps for different shows and companies. As it exists today, it's a very open system, with publicly accessible feeds and the ability to use any app. Don't ruin it. It's not hard to press the "skip forward 30 seconds…
Anecdotally, I listen to a podcast where they make money off merch and Patreon only. No need for advertising.
Because if they do, that's an ad.