That moat only holds out aspiring competitors who compete using the same game Google plays. The person who can come up with a way to show you a grommet when you're thinking cloth clamp will break Google. How many times have you searched for an algorithm, knowing it exists, but not knowing its name? Search is still very broken, and after 20 years of Google is very ripe for disruption.

On the other hand, you can compete with Uber by having a guy in a yellow cab hanging around at the airport.