> I see two options here.

Yes, or perhaps a combination of techniques. E.g. shared database to train an ML system to detect ads. Of course, the downside is that the ad industry will then tweak the ads until they pass the ML test.

> I wouldn't try to productise an app that takes away the main source of income for the radio stations.

I wouldn't think of it as taking away a source of income, but rather as forcing them to find a source that doesn't bother their customers so much. Ad blockers seem to be getting more accepted.