Agree with vbezhenar that Apple doesn't really budge the needle to make this happen. And then you have vendors like Dell that are specifically catering to the Linux market.
https://www.dell.com/en-ca/shop/dell-laptops-netbooks-and-ta...
https://www.dell.com/en-ca/shop/dell-laptops-netbooks-and-ta...
Also, you can buy a GPU but in some ways it is locked down (by NVidia), so as technology progresses we might be moving away from the "generically useful computer" model.
NVidia has always been locked down so that is not news. If you are concerned about the GPU, buy AMD and enjoy their open drivers. Intel is entering this space too with open drivers as well. And who knows, perhaps NVidia might be opening up a bit after all vs. going the other way?
Or should I rather write Android/Linux, ChromeOS/Linux, PuppyLinux, Xandros then?