Comment by weinzierl
"The only way to control wifi is to include your stupid connectivity group [..]"
Not to defend Apple too much, but I think the reason is that the toggles in the control group are interdependent. It would be very confusing if you toggle a button and it causes other toggle buttons to switch state that are either far away on the screen or worse - not visible at all.
Take airplane mode for example. The way it works on iOS[1] is that the act of turning it on toggles the other icons in the group off - once in that moment.
It does not prevent you from switching back on WiFi or Bluetooth. So you can end up with WiFi enabled despite being in airplane mode. To complicate matters, this is not true for mobile data.
A cleaner and more intuitive design in my opinion would have been if the toggles were all independent, with airplane mode overruling all. Of course this would prevent WiFi in airplane mode, which might be a desirable use case, and worse: make people avoid airplane mode when they are mandated to use it.
[1] I am curious how Android solved this. If anyone knows, I'd like to know.
On Android, or at least on my Pixel - toggling on Airplane mode switches off Bluetooth and Wifi, but if you then switch on Bluetooth and/or Wifi whilst Airplane mode is on then next time you go into Airplane mode those will also stay on.
It provides UI feedback that this is happening through the Bluetooth and Internet switches, but thats only because I have those visible. If they're not visible then I wouldn't see whats happening.