The reason why internet access/downloading from the internet isn't a "major" permission is that asking about it would let people conveniently disable it for any offline apps with ads in them to remove the ads. Google doesn't like that, obviously. Of course, you can still disable your wifi/mobile data connection entirely, but it has friction that most average consumers won't trouble themselves with. But if the app asked if you wanted to give it internet access on launch, Google's ad revenue would probably be visibly affected.