I think the Internet warriors are trying to build their own entirely self-sufficient network independent of the state or commercial worlds, which is, as you say, tricky to do only with resources legally available to the general public. Armed forces have had these things nailed down pretty much since the invention of radio.

You could just about squeeze voice down LoRa with a really low-bandwidth codec, as really aggressive codecs can manage < 0.5 kbps. If you want to sacrifice voice quality but use standard codecs, the military MELPe codec has 600 bits/s as one of its standard modes.

The ISPs also have a system that runs without power so long as their batteries (and gensets) last. Typically 1 or 2 days without refuelling.

The real "resilience teams" are going to be at the telcos/ISPs, and they will have dark fibre between their networks and autonomous backup power in their data centres. They will be able to do IRC, VoIP telephony, email, etc. between their networks over statically routed point-to-point IP between their local networks even if BGP and the transit networks go down so they can "black start" the Internet. (Back in my ISP days, I remember reading about there being a private telephone network just for AS operators' NOCs to talk to one another quite independenty of the PSTN.)

For anything that takes even those out (eg. a "Big One" quake in California), you fall back to radio hams and autonomous radio links for the disaster services.

I didn't know about the chip having separate TX and RX pins. There must be a gap in the market for rooftop-to-rooftop LoRa transceivers that don't cost a fortune. Even using something like a 24 dB gain antenna would push range up by a factor of 10 relative to a simple 4 dB antenna, or get a substantial improvement in bandwidth/reliability at the same range. For an even simpler design, you could just put a 20 dB attenuator between the transmit port and the antenna, reducing the effective forward gain of 4 dB, while getting the full 24 dB in the opposite direction. Proper RF engineering details an exercise for the student etc.