I don't think it's beyond their comprehension to ask: "how can I have a chat system that I personally control?" The rest will be taken care of.
Look at the Amnezia VPN. It's an app that helps you buy a VPS from a range of cloud provides, then sets it up, completely from the phone, as an exit node under user control.
I don't see why a chat server cannot be set up and managed this way. It only takes one dedicated developer to produce.