No, because you can make your phone work with other service providers. The dependence on the original hardware vendor is artificial.
> It's intended to be able to blacklist malware
Choice of blacklists, content filters etc. is also orthogonal to the vendor.
Yes. But then it wouldn't be a commercial commodity product, it would be more of a build-your-own DIY kit. Would it be as succesful?
>Choice of blacklists, content filters etc. is also orthogonal to the vendor.
Everything is orthogonal to the vendor, even choice of screen or disk.
But most people don't like choice, want something that mostly works as is. And even for those that do the optionally increases the product complexity, maintainance, and error condition space (integrated vs mix-and-match).
Plus, a few modular laptop and mobile phone designs never sold well.
>Also, I recall a case where MacOS was asking Apple permission whenever the user wished to start an executable. This is nuts.
Not that nuts. It's intended to be able to blacklist malware and such and retroactively disable it, through notarization (basically, registering apps to Apple and them getting a kind of fingerprint).
They could have done it with a local cache (and they probably do in some capacity), but it would still need to ask/sync every now and then.