To gather data? Maybe. It definitely uses the data Google already has, which vastly outweighs the number of people using Ingress. I'd assume Google Maps is far more valuable than Ingress is.
I think it's also worth mentioning for context that Niantic is not owned by Google anymore, though Google is a major investor still.
I think it's also worth mentioning for context that Niantic is not owned by Google anymore, though Google is a major investor still.