Obviously there is no way to know that, but people take these substances for a reason. Does Barry Bonds have the same career without PEDs?
I think that even for athletes that eventually get caught, it may be worth it. Would anyone even know who Lance Armstrong is if he didn't juice? Yes, now he has been outed as a cheat. He can console himself with his millions.
It's just the nature of the beast in a super competitive environment. Everyone is looking for the slightest edge.