Fury, Usyk, Wilder all beat Lewis. This is the most talent rich era in history even guys like Chisora, Zhang, Kabayel, Joyce and Parker would be nightmare heavyweights in the 90s. Holyfield and Tyson would be gatekeepers to todays age, boxing evolves like all sports
Usyk would probably beat him outright, MAYBE a prime 2015 Fury could as well but I wouldn’t exactly bet on it. That being said I’m almost positive that somewhere along the line, some big puncher (Wilder, Zhang, Dubois, whoever you can think of) would randomly chin Lennox.
I've got a lot of respect for Lewis but he's one of the most overrated heavyweights of recent decades.
How much the word "undefeated" is worth ,is of course directly connected to the question how many opponents you faced at all und what quality they were . Lennox fought +40 opponents at heavy and there of course is a chance you loose a fight or two by a lucky punch or simply not being in full shape facing that much guys . In his era lewis fought legends like holyfield or mike tyson . Legends who are not present at today era so it would be easier today but nevertheless hard enough to stay undefeated fighting more than 40 opponents over such a long time .
Usyk V Lennox - I'd back Lennox but I can see the argument for either fighter winning. But Wilder? You need to watch Lennox Lewis V Michael Grant, or even against Golota and Vitali. You can't call youself obsessed with boxing if you really think Wilder would even be competitive against Lennox.
Usyk aside, Lewis would beat all in the division convincingly. Usyk I think would give Lewis nightmares. It's a fight Lewis could win, but its 50/50.
Lewis would go unbeaten in today’s era,unless as happened to him in the past he gets caught with a bomb ! The type of career best punch that Mcall and Rahman landed could be landed on him again without a doubt but not sure who today could land a shot like that,Wilder has the power to do it but just think Lewis far too good skill wise for him. I think it would be Usyk out of today’s era who would run Lewis the closest but Lewis was imo capable of getting the nod over him .
This ignores the fact that Holyfield was faded by the time Lewis fought him, and Tyson was completely shot. And Lewis hardly made a big statement against either.
In any era, beating Lewis is a tough ask. However, because of the way he suffered his losses it is reasonable to think he would be put down for the count by somebody.