It would have made an interesting fight seeing Wilder and Joshua while both were undefeated but it would still make an interesting fight. With both being undefeated I would have backed Wilder to destroy Joshua by going all out for him and giving him a brutal KO within 2 or 3 rounds but now things have changed a lot. Going by the way Joshua out boxed Ruiz to win back the title he lost and going by the way Fury out boxed WIlder, I am not sure Wilder would beat Joshua if they fought today.
I would think right now Fury is top of the current crop of heavyweight boxers. Joshua, Wilder, Ruiz and maybe a couple more are in the same bracket. Then lower than that would be the next group.
@JollyGood - I agree, Wilder(pre Fury defeat) vs Joshua(pre Ruiz defeat) will be a good one. And I think Wilder will knock out Joshua that time. Well obviously, the negotiations that time fell apart and everyone is pointing fingers as who is to blame.