I contest the idea that any two apps are so similar that something as trivial as list-refresh mechanism could push one over the top.
Seriously though, you contest the idea that an interface with interactions which hide complexity and have been shown to be pretty intuitive could be decisive in how users value a product?
Don't bet on UX enhancements ever going away, by the way; people come up with new things all the time. Pull-to-refresh didn't come from any platform vendor; it came from a third party Twitter client.