Comment by idopmstuff

If we assume that there will be an AI that is perfect in terms of ability to find vulnerabilities, cheap to run and widely available to everyone, then anyone can run it on any piece of software before deploying it. All vulnerabilities get found before they can be exploited.

One of the big challenges with cybersecurity is that attackers only need to find one exploit, while defenders need to stop everything. When you have a large surface area and limited resources, it's much easier to be the side that only has to succeed once. AI eliminates the limited resources problem.