...have you ever tried to play on an SLI setup? It's miserable. I abandoned it after the Kepler architecture.

Yes, you get high average framerates and the ability to accelerate some of your games, it looks lovely on paper. What they don't mention is that games with SLI support typically have horrible implementation; while your "average" framerate calculates out to 80-100 at 4K, that doesn't mention dropped frames, framerate dips as low as <5 FPS for seconds at a time, or game instability thanks to roughly-shoehorned visual drivers. And that's just for the games that do support SLI; in most cases (3 out of every 4 AAA titles minimum) there is no SLI support, and trying to run in SLI will actually make the game slower.

And that's just for two cards in SLI. It's even worse for people with three or four!

And who gets the blame? NVidia. Not the game devs who don't code their games with easily-divisible graphics workloads to facilitate SLI, not the API or engine designers who didn't integrate multi-GPU support into their engine, NVidia catches the flak because "their product solution doesn't work out of the box."

No, I completely understand why Nvidia is phasing out SLI support, and I really would not be surprised to see AMD do the same with Vega. I don't think they will, if only because AMD is desperate for a way to set themselves apart from NVidia, and being seen as the "champion of the little guy" is always good PR... plus AMD seems to like working entirely too hard for too little pay-off. But if they dropped CrossFire support after NVidia drops SLI, I wouldn't be upset in any way.