The difference is that a fancy pen and a fancy writing table are functionally the same as a cheap pen and a cheap writing table. One is just a more expensive version of the other.

On the other hand, an aeron chair can be appreciably more comfortable than a cheap alternative, and multiple monitors can reduce the amount of friction a developer experiences (e.g., code in one window, documentation in another). While it's true that good people can make good with little, they can do better with more. If, of course, that "more" is something of actual productive value.