Earlier quoted context omitted.
There are three major national carriers (a fourth launching soon), and an absolute glut of smaller MVNOs which offer devices on their own terms. Most of both the national carriers and the MVNOs will also allow you to bring your own device, which as long as isn't running Android, is probably not encumbered by malicious code. Even if the horrors you suggest are true, consumers would have options to get around them, whi…
Nearly everything you've said was bullshit. Google has never restricted sideloading. Android 12 even enables sideloading further by allowing third party app stores to auto update. AOSP exists. Third party roms exist. All of the devices sold by Google can be unlocked to install third party roms. LineageOS doesn't exist because 'a complete and unassailable monopoly' allows them to.
AOSP is not meaningfully existing on any device sold today.
The fact you can hack your device doesn't change the monopoly Google operates that 99.9% of Android devices are trapped in.