A product that can be described as "X for Y" can't define a new fundamental category.

For example, "Uber for dog walking."

It can transplant insights from one domain to another, but it can't change the game.

The most game-changing things are the ones that aren't possible to capture in a simple statement; they defy categorization into existing boxes.

If you can utter the idea in a short pithy statement then it's not that interesting.

Interestingness is correlated with compressibility.

Not all utterances are as compressed as they could be, but a startup founder gets a ton of practice giving a pithy 5 second explanation for what they do, so if they can't find a pithy formulation for their thing then it likely doesn't exist.