Last year, popular YouTube tech channel Marques Brownlee hosted a blind smartphone camera test that had some shocking results—with the US$300 Pocophone F1 finishing in second place. This year's version is just as interesting, as it threw a similar curveball.
https://www.notebookcheck.net/MKBHD-s-2019-blind-smartphone-camera-test-throws-up-a-few-surprises.447418.0.html
I'm not sure what he's doing with his hair but it looks just...awful.
The study probably could not control for the novelty effects of different lighting. How light affects your mood (and thus possibly drowsiness) will change once you get used to seeing it and it becomes "normal".
Portrait mode is NOT for taking every single photograph. That's what you should learn from this comparison. It's only for specific cases where you really want to blur the background and focus only on one object.