I totally agree, but I also totally disagree that supporting this alternate use case will make the app worse for naive, regular users to discover their grandma

I totally agree, but I also totally disagree that supporting this alternate use case will make the app worse for naive, regular users to discover their grandma is on Signal. Im asking for an alternative canonical source of identity other than an extremely trustworthy telco. Some other conglomerated examples are: Scanning a QR code in person to initiate discovery, or querying other data in the phone's "contacts" PIM app for example, email, or more imaginatively, keybase, or maybe mail out QR codes to residential address for a nominal fee?