You are owner of the hardware, user of the software.
By the way, if you do go down the route of building your own phone, pedophiles, drug dealers, and terrorists will use it, and you're now on the hook to do something about it.
...Back to square one.
We could ban the internet completely and minors wouldn't be any safer.
Which is a great advertisement for GrapheneOS.
There were unofficial statements made by third party android news sites that Catalan police claimed that "Every time we see a Google Pixel, we think it could be a drug dealer"... which, while obviously wrong on its own, is completely different than claiming they are actually arresting people on suspicion of drug dealing merely by using GrapheneOS.
Please stop spreading misinformation.