> What if a 3.5mm cable was a way for your phone to connect to various IoT devices to pass the basic setup data like your wifi SSID and password instead of this goofy process of broadcasting it's own wifi network that you have to connect to.

For what it's worth, the latest Canary (https://canary.is/) is configured via a 3.5mm cable connected to your phone, and the configuration process is relatively smooth compared to the goofy ad-hoc WiFi network approach.