This already exists for YouTube videos (it's called SponsorBlock). It is available as a browser extension that skips them automatically for you.

I think it would be harder with podcasts because of the diversity of available podcast players.

Dynamic Ad Insertion wreaks havoc with this. Podcast eps can have different lengths and segments can have different start times depending on the ad profile of the listener.

And that's just at a single point in time: It's not uncommon for episodes to be re-edited and re-uploaded, or ads to be changed up (with different lengths) over time.