Back in the old days, around the turn of the century, did you know that people actually had portable computers with screens that were visible in direct sunlight? Back in the year 2000, Compaq released the extremely innovative iPAQ H3600 (manufactured by HTC). This device had a transflective screen with side-lighting. Most screens these days are backlit, but with the transflective screen on the iPAQ, the light from the sides within the bezel would illuminate the screen in the shade. The device had it’s own ambient light sensor to detect when side-lighting was necessary. When the device was used in bright sunlight, the reflective display would make the colors on the screen perfectly readable.
See above photo by Arne Hess from 2001 of the iPAQ H3600 with no screen brightness in direct sunlight. How does that compare to any of today’s smartphone screens in direct sunlight?