Not constantly but he was the best throughout that period, and certainly for the longest period of time.
I'm interested in your point, I don't think anyone says he's the best ever but to say he's overrated is a bit odd. He'd walk into every side in the world, now and in the past, so he's right up there in terms of class. Also, few players make it look as easy as Zidane, he could walk past people and they'd have no idea what was going on.