This all sounds sensible and reasonable, but just
at this exact moment, it's hard to feel
totally confident that something bioengineered can't
possibly create a plague inadvertently. And I'm assuming that covid-19
isn't in fact an example.
It made an impression on me, something I read on HN not too long ago, comparing an epidemic to a nuclear reaction - it's really hard to create a critical mass, and when it's dispersed that's it; the really acute problems are local and temporary, despite peoples' fears of invisible radiation and contamination. But once a global epidemic gets going, essentially the whole world may have reached critical mass and has to be diluted. Maybe obvious when stated, but presenting the comparison in the context of the fears people have of nuclear weapons/power is the point.
The probability is low, but the stakes in the near future of biotech seem higher than anything else people can mess with.