Control over hardware isn’t actually the issue at stake here: many Android devices can unlock their bootloaders in a moderately safe way. Go nuts.
It’s a more tricky issue where Google and other parties can restrict access to their services to devices they deem legitimate. Their services, their rules. Your hardware. Different arguments required.
It’s everywhere: Widevine is used to prevent stealing 4K content (incl ATSC 3.0), gaming providers use it for anti-cheat, banks use it to rate limit abuse. It’s not just Android.
(I say this as someone with an Apple Vision Pro running visionOS 1.0 with the hope to jailbreak it one day. I’m actually unable to do whatever I want to their hardware, unlike my Pixel phones.)