Value is relative. Oxygen is extremely valuable if you don't have any, but it's also commonly available.
If Epic had an iOS app store that charged 10% instead of 30% and a reputation among users for not allowing malware, who is going to pay Apple 30%? It doesn't matter how good Apple is in absolute, it matters how good they are relative to the alternatives. Which makes prohibiting the alternatives a means to extract undue rents.
> Beyond that, there would be value in it being the platform that comes preinstalled, even if side loading was a thing.
But this is just the evil to be prevented.
> The brand damage comes from the sum of incompetence of all users (not just the diligent ones) multiplied by the capability to do damage.
The assumption here is that it's legitimate to blame the brand for your own actions, which is absurd. If your self-driving car drives itself into the sea, you can reasonably blame the manufacturer. If you get drunk and drive your car off a pier your own self, this is not the fault of the Ford Motor Company and any attempt to divert blame will be rightfully met with skepticism and ridicule.
Now, you can have a poor design and get blamed for that. For example, the way software is installed on Windows is much worse than the way it is on Linux.
On Windows the default is to run random opaque binaries from arbitrary websites. Windows is full of malware, and it's not just because it's "more popular" or whatever.
On Linux the default is to install software from the system package manager, which contains vetted packages. But you're not in any way limited to one of them. If you want Firefox nightly builds, Mozilla has their own repository. You can install the Nix package manager from the Debian package manager.
You can also download source code from github and compile and run it yourself, which can be dangerous, but that's quite technical and unusual for unsophisticated users to do, and is different from the usual way they install anything which makes them rightfully wary. And this combination works great because you can simultaneously do whatever you want and yet be confident that if you're only doing things in the default way, someone has vetted these things and it's highly unlikely to be malware.
> Plus, if you made it a hassle, the anti-competitive argument you raised with Google rears its head.
We can distinguish between making it a hassle to install random malware and making it a hassle to install a competing store from an established organization the user could plausibly trust to do the vetting for them instead of Apple.
