then it doesn't explain why we survived our own cold war on our own planet

We haven't gotten strongly off planet yet. We survived our first encounter with nuclear war, that doesn't mean that it won't still happen. Indeed, more groups now have access to nuclear weapons. By many estimates the US currently has close to first strike capability on Russia and China, but that may change as China improves its military. And as technology improves, making nukes becomes easier, not harder.

and means we are still at risk of hitting the great filter ourselves, and not a rare technological civilization among the stars like we thought.

Well, this is essentially just the question of whether the Filter is largely in front of us or largely behind us.