Despite what I've written elsewhere in this thread, I really am perplexed by Apple. I don't know why they can't just be nice to (a niche of) their users. Preferably support Nvidia hardware, but at the very least not obstruct it.
One more thing: the Macbook Pro 2013 's got a nVidia GT 750. Yes, its 5 years old; but a laptop in the 3500 bucks range should not be obsolete by now. Which it kind of is, since stuck in High Sierra