I think the only person who could have ever run faster than the current world record of 9.58 is bolt himself in Beijing, and that is and will always be a massive what if. The only way that record will fall is if someone gets that coveted 2.0m/s tailwind and has the race of the century at altitude.
Bolt was decidedly the best in the golden era of sprinting. Let that sink in. The fastest human to have ever lived out of 14+ billions souls, and second isn't even close. I HIGHLY doubt there will ever be another human like him. He was conclusively the best among the best ever. Donovan Bailey was his predecessor as far as potential and top speed with a long stride, but Bolt was still better. Bailey broke the world record after only getting in to sprinting in his mid 20s and was only doing it seriously for 2 years up to that point of his record in 1996. After which, he began to suffer injuries including a catastrophic achilles rupture in 1998. Bailey never had the length of career/time to develop that Bolt had
Ben Johnson (Yes, he was juiced up but they all were in that era), Bailey, Bolt. All generational runners. All Jamaican descent. You could throw Carl Lewis in there but he was Juiced too and was decidedly slower than Ben Johnson by a wide margin. They ran in the same era.
Unless someone comes up here shortly, De Grasse is the next heir to the crown once Bolt/Gatlin/Blake retire. Kids got talent, that's for sure. I'm shocked at his ability to accelerate so late in to the race for someone of his size. He's quite slow out of the blocks like Bolt. Not good for someone his size. Smaller guys need to rely more on their starts, but he has some great top speed. If he can develop more power out of the blocks, he'll be a great for sure.
As for the 400m. That was fucked. I feel priviledged for just having watched it live online lol. Incredible.
On the topic of world records that have stood the test of time. Men's long jump... that's where it's at. 8.90m was set in 1968 and it was only bested once in 1991 by Mike Powell. Nobody has even been close since.
To answer the title. Sometimes, yes I think it is that rare
As for 9.2 or 9.3 being possible. It isn't. That's just a fact. 9.5 is widely regarded as the limit of the human body, and we've reached it