The triangle is meant to suggest that time, scope and money have a relationship. You can pick time and money as the controlling factors, but then you give up on scope - this is not the same thing as "good" although it's usually translated as such ("fast, good, cheap - pick two").

The laptop manufacturers are following the same rules - each new generation of hardware starts off hot, noisy, expensive and a battery hog, to get a little faster. There is then an iterative process to make them cooler, quieter and less expensive for the same speed.

Most projects don't get an iterative process. Why?

1. The client says "that triangle doesn't apply to my project because I'm special. Oh and by the way, can you add in this bit?"

2. The workers try to deliver all of the scope (including the new bit), resulting in the project being late and over budget.

3. The client says "well, those workers weren't very good, but my idea was sound."

Repeat until the client goes bankrupt.