Mostly because the people who want sideloading are using Android. And on Android the situation is constantly getting worse, while on iOS it's largely just sticking to the status quo.
Nevertheless, this serves as an excellent demonstration of the problem with the changes Google are making, since they would allow Google to do exactly what Apple just did.
Nevertheless, this serves as an excellent demonstration of the problem with the changes Google are making, since they would allow Google to do exactly what Apple just did.