I would hazard to guess that latency would be a killer for that. It's painful enough if you have 100ms ping on tactical FPS games like CS:GO for instance, but

I would hazard to guess that latency would be a killer for that. It's painful enough if you have 100ms ping on tactical FPS games like CS:GO for instance, but if the delay in a player's position updating caused a completely different physics cascade to happen (running into a wall rather than a stack of cardboard boxes for instance), that could get pretty jarring to see either the correction occurring constantly or the physics delayed after someone's actions. Of course I'm just theorising - it could be an idea that no-one's implemented yet.