That's one of the canonical dumb investor questions. We try not to ask those. Google could blow most startups out of the water if they chose to focus on building exactly the same thing. What protects startups is that in practice big competitors can only focus on a limited number of things at once.

User indifference is a much, much greater danger for startups than competitors, big or small. So we advise startups to focus on that. What's going to kill you is the Back button, not Google.