And even ignoring the limitations of the sensor, the iPhone isn't even the best smartphone. Due to the fact that it can only record variable framerate video it's basically unusable for professional work, even with the Pro model in ProRes.
Interesting, I've always thought the iphone camera produces extremely good results. Subject to the obvious limitations like not being able to replace the lens! What sort of benchmarks should I be looking at, to really measure the camera's limitations?
The quality difference is massive, and not in favour of the iPhone. Apple has awesome algorithms to post-process these images, but garbage in, garbage out, you can only fix so much.
A larger sensor means you naturally get much better low light capabilities, much better bokeh, and the ability to increase the dynamic range without losing resolution.
What e.g. Google Pixels call "HDR+" is what high end Canon cameras can do at 24 frames a second, due to the higher dynamic range of their sensors and the integration of two independent gain circuits.