I had a relevant thought just the other day: why do our chat apps (sms, wechat, etc) need the ability to message someone without first meeting face to face? May

I had a relevant thought just the other day: why do our chat apps (sms, wechat, etc) need the ability to message someone without first meeting face to face? Maybe just use a QR code you scan from their phone and that’s it. If anyone gets your phone number they can send you unwanted spam because it’s “push”