I'm sure they do the same testing but because they control all the hardware and there are so few models to test on, it makes things much easier. I don't think there's anything in particular about Apple's process that would scale better to the number of devices supported by Android.

You think Apple tests their phones with all 120 carriers with every point release?

I don't, and that's not what I said. My point was that Apple doesn't have to think about testing vendor-specific bloatware every release across a wide range of very different devices.

If they don't; its going to be hell when people can't call 112/911

Yes because I’m sure an update to Safari and messages will cause the dialer not to work without proper testing…

Tbf the pixel phone does have issues making emergency calls, every time they claim to have fixed it we hear another report of an updated phone not being able to connect.