protected by PGP

Someone here recently linked to this gem https://www.latacora.com/blog/2019/07/16/the-pgp-problem/

The article warns PGP over Email is a safety concern. They suggest Signal instead. (And several other tools to replace PGP)

E-mail is horrible for privacy, spam, instant messaging, etc. PGP "works" in very limited scenarios, and e-mail is not really one of them.

Plus these two statements seem unplausible for me:

we can assume you're protected by PGP when writing to most users,

and

and with the added effect of not needing to convince anyone to install anything since from their end it's just an email.

I disagree with the first statement, most users don't know what PGP is and therefore don't have keys, so you can't encrypt anything to them. The only way most users would use PGP is if something sets it up for them, alá protonmail or my using some special client. Since you've said that from their end it is just an e-mail, how does Deltachat add any meaningful encryption?

I have been interested in trying out LoRA and just need to get some devices built. Though I am not as concerned about the super privacy part (thought that is nice). I am thinking that it would be good for emergency situations like shit that has happened with the south-east. Even if the communications would be limited to text, shit is good as long as I can use simple solar panels and battery banks.

Meshtastic can do this, and leverage other nodes as relays.