There are many online radio stations without ads, and you can already wall off advertising with something like PiHole or extensions like uBlockO. I never hear or see ads anymore :)
If you're looking at a blog that might've been presented with ads, but you're not seeing those ads, well that's nice. I also rarely see those ads. But how do you know whether the blog itself is an ad? That's the more insidious problem.
There are also many very good publicly funded radio stations out there. Shout out to WNRN in central Virginia.