I've started to listen to local college radio. I like the amateurishness of it. The physicality of radio, in a community, I think is still a think. At least of some stations.

I'm still considering renting some shortwave air time and broadcasting on WRMI.

In the US it's actually legal to broadcast on both FM and AM. The legal FM limits are maybe a parking lot, but AM can get 2 miles. This is without a license. See "part 15".

And there is no restrictions I'm pretty sure. So you could broadcast encrypted audio if you wanted.

I like the concept of meshtastic, but don't discount perhaps older and simpler methods if you are OK with the geographic limits.