Everyone has explained what most IOT devices do, but honestly, the AP approach is a terrible customer experience. It requires changing your associated network on your phone twice. Furthermore, I believe both Android and IOS do not allow apps to do this, so they user has to switch from the app to the os WiFi screen, then back again, then back to the WiFi screen, then usually back to the app. (Maybe this policy was changed?)
Also, it kind of blows that you need an app to configure an IOT device at all.
Doesn't need an app. If it does, you are right, it sucks. OTOH, if the normal usage needs app anyway, then requiring the same app for configuration isn't an extra nuisance.
Configuration is normally done once or maybe twice per product lifetime.
Changing to different WiFi networks, OTOH, is done on a daily basis by many - think about visiting cafes, other public spaces, friends, etc.
I do it maybe 3-4 times a day on average.
If changing the WiFi network twice
as a single-time event is a nuisance, the mobile device is broken beyond use, and using it is a major PITA anyway. It's not a problem of the IoT configuration procedure, but a problem of the broken phone UI. The user has already accepted this nuisance if using such broken device.
Of course, having everything configure and "just work" automatically would be very nice. Such attempts often end up being total failures, or cause total vendor-lock-in. The described procedure (without an app) takes approx. 60 seconds of manual user intervention (including changing the WiFi network twice), but it works, will always work, and work with any device in existence.