[leni536]

I recently learned that there is a business doing exactly that:

https://iode.tech/

I don't think it's high volume, I think this is done by some of the microg folks.

But OEMs probably do everything in their power to make this business model unviable or at least not scale.

[microtonal]

It is one of many projects that make alternative, AOSP-based operating systems (e.g. GrapheneOS, LineageOS, /e/OS), and some of them sell devices for an additional source of income (e.g. Murena who develop /e/OS also does this).