>We could end up in a cyber war aimed at each other's critical infrastructure (which has a real potential to kill people), without ever really deciding we wanted to go to war.

We're already there. Although most of it happens by way of modern day privateering. The Colonial pipeline hack was only possible because of the ability of de facto state sponsored groups like Darkside to exist. As long as there is an implicit guarantee of no consequences for attacking the west, they will continue to escalate.