Being knocked down by a heavy hitter like Wilder is not a big deal. Fury jokes around inside the ring, hence he gets dropped.
Which one of the 4 knockdowns was Fury joking around on? The fact he doesn't take the task at hand seriously, makes me doubt how dominant he would be in other eras.
I see. To your point, if Fury fools around enough to get dropped 4 times by a limited fighter like Wilder, what do you think a Lennox Lewis, Ali, M. Tyson or Holmes would do to that same guy? All these men from different eras, all levels above Wilder in both skills and ring smarts. Would Fury really take it seriously enough to be dominant in the other eras?
Fury is mentally unstable. It depends entirely up to him if he took it seriously. The Fury that showed up against Wilder 3 would get dropped and possibly stopped by 40 year old Wlad.