TL;DR: Use it to decide whether an industry is attractive before you commit time or capital.
It helps you see where margins get killed: competition, substitutes, buyer power, supplier power, or new entrants.
Airlines are notorious: high fixed costs, heavy competition, little loyalty, and price-sensitive buyers.
People fill the whole template and learn nothing. The point is to identify what destroys margins.
Use it to decide whether an industry is attractive before you commit time or capital.
You are here because this concept becomes more useful after Market Reality and before Competitive Advantage.