I think you are confusing your personal use case with everybody's use case. What's a "normal app" anyway? Did you mean to say "apps I use on a daily basis"? Because of the 17 apps on my home screen, 6 do not have a functional requirement for internet connectivity. I bet for users in emerging markets this ratio might be even higher.
> If a user ONLY gets a permissions pop-up when it actually matters...
For most people, spending money is something that actually matters. Again, just because you don't have metered data, doesn't mean everyone else is in the same situation.
> Just an obstruction which teaches the users permissions can be safely ignored
Google manages to sort millions of search results by relevancy, I'm sure they can do the same for app permissions.