Ok, let’s dial it back a bit…
Bare-bones example here. If you buy CD / DVD / BluRay etc.., of music or a movie. Is it illegal to back it up digitally in case something happens to the physical copy (which is in fact a modification of the product you purchase)? No. As long as you are not distributing it, selling it, etc.. It stays in your private collection. Does this mean the movie studio that produced the movie or the musician that produced the music is entitled to another payment for my protecting my investment? No.
I am trying to educate you here on WHAT AOSP is. The Android Open Source Project has been around for 20+ years. Google made Android free. How the manufacturer customizes it is their own business. How the end user customizes their device is their business as well. I disable / uninstall most Google applications on my phone because I CHOOSE to use another product in place of theirs. There is nothing illegal or illicit about this practice. It is what it always has been - the user’s freedom to do as they wish the the product they purchase. That is the nature of AOSP and always will be.
Even Google sells Pixel devices - and they encourage customers and developers to install and use custom firmware on their devices, thus wiping out anything that was preinstalled. There is nothing illegal or illicit about this either.
AOSP protects the end-user as well as the company that develops Android on their devices. What the USER chooses to do is up to them. Zuck knows this, and anyone that develops an Android app knows this. It is not Nothing’s job to police 8 billion people, and it can’t be policed or controlled because of the agreement at the very core of developing anything on Android has.
Sure, bake it in to your build of Android software, but the user can still do what they want. There is no “locking it down”.
Whether or not you feel this is fair that a user has the right to do what they want to do with their personal property is (not being mean or condescending here - it’s just the harsh truth) is your opinion and you are entitled to it. It still doesn’t change a single thing about Android, AOSP, and users having the freedom to do as they wish.