History & CultureMental model
"What if not?" is a measuring tool, not a game.
To say how important a cause was, you have to ask what would have happened without it. In 1964 economist Robert Fogel calculated what the USA would have achieved without railways: using canals and roads, economic output in 1890 would have been only a few percent smaller. Railways mattered, but weren't "indispensable". Only the counter-scenario makes causes measurable.
Useful: When someone says "X changed everything", ask: what would have happened without X, and how sure are we?
Source: en.wikipedia.org