Heavy weight boxing is horrible today. In the US they are all going into the NFL to make money. Very few boxing gyms to be found. Back in the day there were 20 fighters that could have beat Fury to a pulp. He's a glorified journeyman. Back in the day a fighter like this would be fighting in high school gyms for a $400 pay day.
The 90's was one of the strongest era's in HW history and yet there were several boxers clearly inferior to Fury who won titles during that decade (Seldon, Moorer, Bentt, Hide, Akinwande...etc).
Fury may not have been rated number one but he'd comfortably be among the better fighters of any era.