I'm running 3 Way SLI with 1080 Kingpin. As for newer games getting away from it, Far Cry 5 is not the case, runs like a charm and actually solves an issue with screen flickering when you activate 3 way SLI, I'm running it on 3 screen 2K each, at 60+ FPS, highly optimized game.
Battlefield 1, is a different thing. That would run better in two way SLI, or even with a single card. We are used to be disappointed by EA anyways.
Battlefield 4 runs perfect, but will use all available resources, as it seems to be very inefficient with newer cards.
SimCity 5, forget about SLI at all.
It's been kind of complicated to use 3 way SLI, but in some cases you don't even have to deal with profile inspector. Stability has gotten better with the latest drivers.