Android isn't a Linux desktop environment. I'd barely even call it Linux. It uses its own drawing layer that's not X or Wayland, a mounting system that makes no sense and changes with every release, is filled with tons of proprietary stuff ... I mean, it's the Linux kernel and pretty much nothing else.

Linux is a kernel, I explicitly wrote GNU/Linux, and if it makes sense to you or not, it doesn't matter.

The reality is that Android/Linux has a windowing system, supports external monitors, keyboards and mice.

A question unrelated to the post .. Why would you say that the mounting system doesn't make sense in Android? Not rebuking what you said, just want to understand.

I detailed one issue I ran into here on this post:

https://android.stackexchange.com/questions/124575/mount-an-...

Looks like some comments were added three years later. The entire mounting system between the Linux command-line/system interface and the Android UI is terrible disconnected and the way to trigger events in one changes in every single release. Having just a knowledge of Linux is not going to help you debug problems with Android.

Android also does a lot of crazy/non-standard SELinux isolation stuff. I do a longer/more complete rant on Android from a few years back here:

https://battlepenguin.com/tech/android-fragmentation/

This is why the GNU/Linux vs Linux distinction is useful.