As an owner of an iPhone 7 and a Pixel I'd say there are not many. Google Assistant is way ahead of Siri at pretty much every imaginable task, and Google Photos can do a lot more than iOS Photos.
That said, none of those features interest me much. And I'm not sure how many average consumers they do interest. It's more of a 'oh, that's cool I guess'. I prefer my iPhone 7 still.