A do-it-yourself wireless mesh network that you can use, say, while hiking. You don't have to be in range of the furthest person, you just have to be in range of someone that's in range of someone, and so on, up to the furthest person (or device).
Meshtastic will work without centralized DNS.
It will work without central servers.
User accounts are self-hosted, meaning the user is in full control. It's unknown or is not applicable if Meshtastic supports cryptocurrency monetization.