Yes. Radio and podcasts aren't entitled to their business model working, especially if their business model involves purposefully exposing their listeners to harmful material.

I believe ad blocking is ethically justified on the grounds that it's just defending yourself from other's unethical behavior, and that you're entitled to do so - claiming otherwise would imply you're supposed to be forced to sit through entirety of a performance. That would be absurd invasion of your autonomy.

Also note that you are not paying radio hosts/podcast authors through advertisements. The ad network is. The exact payout structure is complicated and agreed upon without involving me the listener, but it boils down to parties speculating that a fraction of ad impressions will turn into eventual boost in sales, and money flowing from advertisers, through networks, to publishers, based on that expectation. At no point was I consulted in this, so I feel no obligation towards participating in whatever deals these parties set up between themselves - doubly so given that I'm being harmed by those deals.

Is leaving the room during a television commercial break also stealing?