It is cool! The barrier to entry is relatively low. The only thing to really worry about is:

1. What band/frequency is appropriate for you country.
2. Are there others around to which you can connect?

If there's not a lot of people around it's not the end of the world. Nodes can connect over the Internet via MQTT servers. Yes, this defeats the purpose of having an offline/decentralized communication platform, but it is a good stop gap until more nodes are put up.

Here's a sample of what I can see in a somewhat large-ish Midwest City in the US (there's about 63 nodes I can reach by hopping through relays).

It allows us to make a mesh network (interconnected nodes where you can contact a node even if it's not in range for you, by using other nodes) with Lora radio devices. Lora is slow but has long range. I think it works better when you have line of sight, like if someone can put a node on a mountain, it would help everyone.

I think people might have sent audio with it but it's mostly useful for text messages. It could be useful if the Internet is down, maybe, but it's more like a toy.