> the ones who do know don't care because they wouldn't be able to (technical knowledge) or want to root/unlock and utilize the capabilities
This is a good point. Some of that is perhaps self-perpetuating: Why root if there's nothing you can do with root? And why develop stuff you can do with root if there's nobody who can use it? If there weren't so much active suppression of software freedom by manufacturers maybe the situation would change and the benefits of consumers having full control of their devices would be more apparent.
Just my opinion from many conversations with normies about this: It's because most of them don't know (the marketing material from these companies certainly doesn't advertise it), and the ones who do know don't care because they wouldn't be able to (technical knowledge) or want to root/unlock and utilize the capabilities.