Sullivan fought in a time before the jab or slipping was invented. I can't believe it needs to be said but KO of the first minute of the first round In 1891 the 100m sprinting record was 10.8. A 50 year old has ran a 10.8
The first paragraph is very insightful, but the current 100m sprint record is only 9.6. I bet if you gave that 10.8 sprinter a modern surface, shoes, starting block, precise timing technology, etc you might get them sub 10 the day they step out of the time machine. I feel like the drop in marathon time from 3:28 to 2:01 is more relevant, since both marathon and boxing have that psychological endurance element. I feel like Wilder is the type to fire his shot regardless of whether he has hand protection. I forgot JLS was so small. The next generation (Jeffries, etc) had some bigger guys, right? Honestly my knowledge of the early game is very sparse. I don't know how all of you are able to study it so thoroughly to develop these opinions.
I'm not that familiar with it compared to the true experts, but it's really a question of rules as much as anything. Sullivan is 5'10", 190 or so at his best. His technique includes wrestling / throws, and the punching technique was built for bare knuckled strikes. To win under London Prize Ring Rules, you had to knock your opponent out for a 30 count, so Wilder's puncher status is a bit less central. On the other hand, Wilder came from a bigger talent pool, and is a very large and well trained athlete compared to Sullivan. So I don't know how it turns out.