The laws here are in a pretty sad shape. For example, did you know that companies that synthesize DNA and RNA are not legally required to screen their orders for known hazards, and many don't? This is bad, but it hasn't been a problem yet in part because the knowledge necessary to interact with these companies and figure out what you'd want to synthesize if you were trying to cause massive harm has been limited to a relatively small number of people with better things to do. LLMs lower the bar for causing harm by opening this up to a lot more people.
Long term limiting LLMs isn't a solution, but while we get the laws and practices around risky biology into better shape I don't see how else we avoid engineered pandemics in the meantime.
(I'm putting my money where my mouth is: I left my bigtech job to work on detecting engineered pathogens.)