I mean, your smartphone already knows how to talk on 600 megahertz, 700 megahertz, 800 megahertz, 1.7 gigahertz, 1.9 gigahertz, 2.1 gigahertz, 2.4 gigahertz, 3 gigahertz, 5 gigahertz, 6 gigahertz, etc. I see absolutely no reason it would be unable to talk on 915 megahertz.
It’s not just about the frequency. It’s about the modulation. You need new/additional radio hardware. Constantly being on another band eats more battery, too.
But as we’ve seen in busy areas, there’s just not enough bandwidth with many nodes on LoRa. It’d get congested real fast if it were built-in to mainstream phones.
Using the hardware that’s there, something like briar let’s you get your messages routed through whichever means. Bluetooth mesh, internet or tor.