They use the same frequencies depending where you’re located. Meshtastic is P2P where as Helium you need gateways to connect to in a more managed network. LoRa compared to LoRaWAN. 

 Helium has always felt like a Big Tech LoRa grift to me.

Have you been following Beechat? 

 They got popular because of the rewards system in place.

I hadn’t heard of Beechat, but it looks like it’s basically the same thing as Meshtastic?