And you'll typically need 4-5x as many of them, and/or they bill 4-5x as many hours. This is not theory. I've seen this happen in reality, over and over again. Does this happen in all cases? No. But I've seen it happen enough that I make decisions based on it. And look at Mythical Man Month for a primer on why larger teams tend to be worse than smaller ones (worse efficiency, more communication overhead, more cheese-moving, etc.)
Having flashbacks to the worse quality startups I've seen that had 5+ person teams in Uruguay, Pakistan, etc. when they could have had the same work accomplished by 1-2 more elite, and local, same timezone, same culture/language, more "expensive" (nominally, but not overall) Americans or Europeans.