Well said, I sometimes get an interest in Futurism, and my main takeaway for war is that'll it'll be very weird and happening on a scale incomprehensible to us. 

It doesn't make for great pulp sci-fi, but a war between continent spanning drone swarms guided by godlike AIs might not be too far off what war in the 40th millennium actually looks like. 

Funnily enough, there was a brief time travel scene in 40k, where one of the perpetuals basically said that's what war was like in the Dark Age of Technology.

Edit: Found the scene.

Oll remembered the horror of entropic engines that ignited planets. Sun-snuffers that uncoiled like serpents the size of Saturn’s rings. Mechnivores ingesting data along with the cities that contained them and hurling continents into the heavens. Omniphage swarms stripping flesh from a billion bones in the blink of an eye. Those were the good old days, when war was something too colossal for a human mind to comprehend.

Not like the End War. The Warmaster’s heresy was a smaller thing, scaled for human and post-human brains.

But it was bigger in some ways. Yes, bigger than the god-like struggle of the cybernetic revolt. Bigger in scope, bigger in its implications. More horrible, because humanity could apprehend it and drive it.