> There is no interference pattern from a single photon as it hits the registration device at a particular place. But collect a big enough sequence of single photon measurements and it emerges.
The same could be said of the entirely unsurprising many-photon case. The individual photons aren't demonstrating the interference pattern, just the "big enough sequence of single photon measurements". Again, that's not the interesting part of the double slit experiment. We're perfectly used to the concept of a collection of many interacting particles having wave-like properties.
The double slit experiment has non-interacting photons demonstrating wave-like properties.
The same could be said of the entirely unsurprising many-photon case. The individual photons aren't demonstrating the interference pattern, just the "big enough sequence of single photon measurements". Again, that's not the interesting part of the double slit experiment. We're perfectly used to the concept of a collection of many interacting particles having wave-like properties.
The double slit experiment has non-interacting photons demonstrating wave-like properties.