Right, but the internet survived the Melissa virus and other early widespread worm attacks. They caused widespread disruption and economic damage, but they weren’t the end of the world. And besides, at present people are using AI to find and patch software at a faster rate than they are using it to compromise software (more dollars are allocated to security these days).
IMHO the biggest problems will be with poorly written AI slop software, probably small business crapware produced with minimal investment (maybe entirely without an experienced developer) and legacy equipment that’s been abandoned by the manufacturer. This will lead to disruption but not catastrophe.