Look, Bonds, Sosa and Mac could always hit the ball. That isn’t in question. But what is in question is, were they always that prolific? The answer is no. When you are a HR hitter, it is a question of squaring up the ball. Don’t square it up and unless you are uber strong, it will not carry.
With those three and anyone taking muscle building steroids, what ever exertion they make probably has more force behind it. I’d guess some of the long fly balls that resulted in long outs would probably make it over the fence with more force in the steroid using batter’s swing.