For human facing privacy and security information overload is a genuinely huge issue. What value do you assert exists for a "scary dialog" for Camera, software from Apple? After all, for that to even mean anything you must by definition be trusting iOS, software from Apple. On the other hand it's perfectly reasonable to not have the same level of trust in 3rd parties. 3rd parties do not share the same financial relationship or incentives that Apple has with its customers. Nor the same culture, nor necessarily scrutiny or technical acumen or even controlling legal regime.
You certainly do not need to trust Apple at all in general, you can run Linux, the BSDs, Windows, ChromeOS, Android or (happily!) various improving Linux phones that are extremely open. But if you decide to run Apple specifically, then you must indeed trust them.
Edit: Also, "fearmongering" is a ridiculous bit of bait. I mean, 2020 on HN and you're suggesting random 3rd party apps accessing camera/location/whatever is not the slightest issue? Ok.
The only complaint here seems to be that the bootstrapping for granting permission is part of the initial device setup screen and location services, but that seems perfectly reasonable in line with user expectations for default system services on fresh system. I strongly disagree that "fairness" somehow is a valid complaint here in the way GP suggested. On the contrary, insisting Apple is equivalent to 3rd parties is itself "unfair" as well as wrong.
There's also another way they exempt themselves, by allowing you to disable microphone for third-party apps but not offering to disable microphone access for Voice Memos, Camera, etc. On Android I can disable the microphone for any first-party app, even the Phone app which obviously needs it.