Steroids help. No one can deny that. The average person might get into pretty good shape using steroids without much effort. You can gain muscle by taking steroids and not training as your body processes protein better.
None of these people taking steroids will ever look like a pro bodybuilder as they don't have the dedication, mental mindset, determination, or work ethic to get there. Pro bodybuilders are a special kind. It's all built on consistency, day in and day out, every day, every week, every month, every year. Every meal is calculated, and every training session is calculated, logged and analysed.
Steroids certainly helped in his bodybuilding, but his single-mindedness made him the best bodybuilder of his time. The same single-mindedness got him a film career and then a political career.
The difference with Lance Armstrong is that pro bodybuilding competitions have never had rules banning performance enhancing drugs. Cycling isn't judge on your body being the biggest unnatural freaks on stage where performance-enhancing-drugs is a given unless you are competing in a completely natural class.