Pancreatic cancer is pretty fatal even without an alternative approach
He had the one treatable form of pancreatic cancer though. Of course that’s not a guarantee that treatment would have saved him but it would have greatly increased his odds of surviving.
In that case you can still use open source messaging apps that you could compile yourself if you don’t trust the distributor.
I would assume that people in a similar demographics are interested in similar topics. Adjusting the answer to a person within a demographic would therefore adjust it to all people within that demographic and interested in that specific topic.
Or maybe it’s just the nature of the answer being more personal that makes it more appealing to people in general, no matter their background.
OpenKeychain has an implementation like this (not 100%) maybe that fits your use case?
https://www.openkeychain.org/