OP:
> As long as the AI (that anyone can access) can also spit out an equally powerful antiviral.
You:
> Yeah - that's not how that works I believe. Some problems are harder than others, and the optimal virus it could produce could take orders or magnitude more time/computation.(edit:to produce an effective antiviral)
With «not how that works» you, I think, implied that there's no reason to expect that proliferation of AI could offset (or indeed decrease) the risk from AI accelerating GoF research. Admittedly I'm not sure specifically about someone's local model designing an antiviral to a new pandemic, that'd certainly happen first on an institutional cluster. But local systems can still assist with e.g. monitoring environment data for new DNA signatures and reporting curious finds.
Anyway, I understood this, in conjunction with other risks you pitched, as a general issue of AI capabilities not offsetting AI risks. I believe this needs better arguments, because many real-world scenarios seem advantageous to the defending side, even when it's "weaker" in terms of resources, and disadvantageous to attacks, which run against natural constraints. An AI filter can see past clever attempts to hide signatures of a spam message (perhaps well enough that passing spam will just stop looking like anything a human would write or read and will be detected by simple heuristics). An AI-fortified firewall will be vastly more reliable than anything we've got now, possibly strong enough to ward off superintelligent attackers. An AI biomed assistant can design vaccines and medicines against entire classes of pathogens, in a way that cannot be overcome just by generating more variants in a wet lab. This is not wishful thinking – it's a very real question. People often fear that AI proliferation as something like everyone getting tabletop nukes, and I think this is an entirely wrong analogy, because it's impossible for physical reasons to build nuclear-powered shields or something; but in the realm of resource-constrained intelligence «that's not how it works».
> and his hurdle is having access to restricted hardware - how hard is it to get the AI to design the hardware?
Pretty hard. But more importantly, everyone interested knows the designs. It's just capital-intensive to the point of impossibility, you need a lot of precision and high-purity materials, so you're forced to buy from established vendors. People tend to overestimate the importance of secrecy in keeping the world livable; I think it's largely a result of propaganda by state security, which is constitutionally biased towards this line of thinking.
In the limit of this logic with AI helping design some precursor to a threat, you'd be just left arguing that AI can make civilization so efficient, any crackpot wannabe comic villain will be able to hide a full supply chain, from mining raw minerals to microchips and bioweapons, on his Texan ranch. Some people bite that bullet, and sure, I think that is doable. But are you sure that a civilization of such logistical prowess would be anything like our one? That it would still be vulnerable to crackpots spreading COVID? That it wouldn't just crank out, say, a few billion UV air purifiers for good measure, because that'd be cheaper than checking?
Be that as it may, I'll pick the prospect of that civilization over the current one, to say nothing of stagnation AI-risk hall monitors want to impose.