Rob Horning spies an article in the Walrus about the possible downsides:
[Neurological researcher Véronique Bohbot fears that overreliance on GPS, which demands a hyper-pure form of stimulus-response behaviour, will result in our using the spatial capabilities of the hippocampus less, and that it will in turn get smaller. Other studies have tied atrophy of the hippocampus to increased risk of dementia. “We can only draw an inference,” Bohbot acknowledges. “But there’s a logical conclusion that people could increase their risk of atrophy if they stop paying attention to where they are and where they go.”
No, he's not talking about the Republicans.