IMHO, from what I've seen in boxing, the majority of the World Class fighters bent the rules (and broke them at times) to whatever degree they thought they could get away with. By the way, it's always been the same in almost all sports (and even Poker, for anyone who's interested). Using PEDs is just another way of doing what's been done, probably from the beginning (getting an edge any way possible), and I'm not even sure when PEDs' use started in boxing, but I'd bet it was before most of us think. I can assure you that Holyfield was NOT the first one to load up on them.
To adults. You don't have to prove Santa Klaus doesn't. You don't have to prove Bigfoot doesn't exist. You don't have to prove you didn't commit a crime. You don't have to prove that you are not the queen of England. Someone making a claim has the burden of proof. That is the adult world.
So where's your proof Holyfield took steroids? Drug test? Video evidence? Giving us your opinion about how he looked is not proof. So go on Mr Adult, show us the proof then? Where's your proof Holyfield's opponents were clean? By the way, in the court of law, you do have to prove your innocence (you didn't commit a crime) if you are a suspect. So therefore, you've been proven wrong (again). Merely claiming I don't have to prove it doesn't mean you don't have to prove it. Yes you do buddy. And you also need to prove you can't prove a negative if you claim you can't prove a negative. The standard of logic remains the same for positive or negative proof.
I doubt George Foreman took anything doing his prime or doing his comeback. I don't think Riddick Bowe, Tony Tucker, Buster Douglas, Michael Dokes took anything either but most heavyweights from the 80's to this day are on something.