MacOS is very far from Unix ideology at this point. It’s not even possible anymore to install things you compile without a bunch of red tape scary warnings. You can’t make new folders in /. iOS has tons of private APIs that only Apple gets to use to make their apps and services the only viable choice, eg iCloud can upload photos in the background but Google Photos times out, even the location sharing hack doesn’t fix this.
Apple doesn’t do it because it’s only a small percentage of users who even know what it is to want it, and they’re already well-served by third party tools. Look at how long it took for widgets to come to iOS. Apple isn’t usually the first mover when it comes to software stuff like this, they like to sit back and let other devs solve problems then see how it plays in the market first before launching a better-integrated version themselves (sometimes in a way that only they can do because again private APIs) with only the basic features included.
Apple doesn’t do it because it’s only a small percentage of users who even know what it is to want it, and they’re already well-served by third party tools. Look at how long it took for widgets to come to iOS. Apple isn’t usually the first mover when it comes to software stuff like this, they like to sit back and let other devs solve problems then see how it plays in the market first before launching a better-integrated version themselves (sometimes in a way that only they can do because again private APIs) with only the basic features included.