Doing a bit of A=B=C logic, that's actually true Ray Mercer did call Morrison the hardest puncher he ever fought. Foreman ranked him up there, even called him the best body puncher. He's a bit underrated as a puncher on this forum IMO.
The correct answer is almost always the modern fighter. In this case Willard was not even particularly good for his time period.
Again, I really don't think that how good a fighter looks on film, is a good indicator of how well they would fare head to head. For example Zab Judah looks a lot better on film, than Carlos Baldomir. It is useful to study film, but you have to take results into account as well!
I guess it depends on what way you look at it. Willard was pretty poor compared to what Johnson had been but he was in right place at right time to become the man.
Yes he was poor compared to Johnson, but that is like saying that he was the Michael Spinks of the era, as opposed to the Larry Holmes of the era.
I'd say the gap was substantially larger than that. Hard to know for sure but I suspect that other poor heavyweights might have defeated Johnson that night too.
I would not be shocked if Pinklon Thomas could have beaten the version of Holmes that Michael Spinks beat.
Possibly but Thomas was a top heavyweight at the time. Willard may have been a top heavyweight in his but almost by default such was the dearth of talent around. In short Willard's status was high for his time but his abilities were not.
But when those results are 100 (or more) years apart, we can't just deduce that someone from far, far back with a good record, would beat a modern boxer with a less steller record. If a boxer was able to become a world champion in the 1890s, it's not a given that he would beat today's boxers, who are unable to capture a world crown. There are differences between eras - which you seem reluctant to recognize.