Depends what you mean by strong AI. The best we know for sure we can do is much faster human intelligence minus the stupid parts, and with more memory. That’s pretty danged smart, but if you think that’s not ‘strong AI’ then it isn’t much of a stretch to suppose that that’s the end of the road—we’re close enough to optimal that once you’ve fixed the blatant flaws you’re well into diminishing returns territory.
Depends what you mean by strong AI. The best we know for sure we can do is much faster human intelligence minus the stupid parts, and with more memory. That’s pretty danged smart, but if you think that’s not ‘strong AI’ then it isn’t much of a stretch to suppose that that’s the end of the road—we’re close enough to optimal that once you’ve fixed the blatant flaws you’re well into diminishing returns territory.