Linux instead of Android - how realistic is it?

Question

linux

1. It seems that Linux has worse compatibility, and Android is installed on all ARM boards - if so, what's the matter?
   
2. Android is also based on Linux and its source code is open - does this mean that you can just compile it without unnecessary functionality? If so, is it difficult for Android experts?
   

The goal is to maximize the release of RAM on android dongles and TV boxes.

Answer 1

Android is an operating system based on the Linux kernel.
Linux is just the kernel.
Your question doesn't make sense.

Answer 2

The whole problem of Linux on tablets and other useless things is the lack of adequate modules (read firewood) for hardware, because all hardware modules in android firmware are usually closed by the manufacturer.