Does it, though? There are many, many, many AOSP-based systems. DJI remote controllers run AOSP, and of course there is LineageOS and GrapheneOS.
I can read the sources of AOSP, I can modify it, build it and install it on my device.
I can read the sources of AOSP to find bugs or security issues.
I can read the sources of AOSP to understand how it works and get inspiration for my own projects.
What does it compromise to you?
Maybe you're unhappy about the fact that it is not open development, but that's a completely different question and many, many open source projects are like that. I have offered PRs to multiple projects that never bothered reviewing them because they did not care, and that is exactly how open source works.
There are so many reasons to complain about Google, the fact that Android is open source is not one of them.
