We’ve reached a day when a fast server can handle almost any single load that is thrown at it. For a few thousand dollars, perhaps $5K to pick a round number, you can have a system that will perform adequately to almost any load. Because of this performance testing is becoming a luxury that few can afford.
Of course, there are some organizations that will find that their applications can not be served on a single server or even a small farm of servers. Their tasks will be so large, difficult, or expansive, that no single piece of hardware can solve the need—however, the number of organizations with those needs is dramatically shrinking.