As said any number of times, unless there is a major problem with the display, accuracy is the only metric of "best". And it is a series of measurements stated as an average delta from a value considered to be "perfect". So all the points measured, measure their distance from perfect, average that, best display will have the lowest number.
Major problems could include inappropriate resolution (1080p on a huge screen), inappropriate pixel configuration given the resulotion (the OnePlus 3 example), poor build quality, terrible power efficiency, etc. Mistakes or missteps by the OEM. Most of the things that are on your list are things that are custom software enhancements to the device that the display is paired with, not part of the display hardware/software configuration itself. They do enhance the viewing experience of some content, but they would do so regardless of the quality of the display, to a similar relative extent.
Power efficiency is the remaining topic, and that's still a mixed bag between LCD and OLED because too much is dependent on how much content is on the display, what color it is, etc - OLED's advantage is for mostly dark screens and there's still a tipping point where LCD becomes equally and then more efficient.
So if it is true that the iPhone 7 is still more accurate, the only reasonable conclusion is that it is still the best display out there. And we're not going to know the answer to that until we know the average delta measurements on grayscale, whitepoint and the respective color gamuts the device utilizes.