Information about Motorolas. I had G5 plus and now G100. Both have PWM below 65% brightness but are absolutely discomfort-free to use above 65%.
I would hope people would try out G100 and really see how it does not irritate the eyes AT ALL no matter how long it is used. I can read books or watch movies or whatever 24/7 if I wanted, no eye strain at all.
On the other hand, I have tried many phones without PWM and which I have personally confirmed not to have any sort of PWM by testing with a DSLR, but they cause immediate and severe eye strain.
I would suggest letting go of the idea that the screen has to be PWM free at all brightness levels. Before Motorolas I had Sony Xperia phones which all had PWM below 35% brightness. I just did not use auto brightness and those were absolutely problem-free.
Nowadays PWM is starting to be the smallest of our problems since most displays and phones can be used without PWM at certain brightness levels, but yet most displays and phones still do cause eye strain.
Motorola G200 for example, reportedly has 89 Khz PWM, so you would think it is such a high frequency that it would not cause any problems anymore. Yet my eyes are still fried though I stopped using G200 about 48h ago.
Either it is the high frequency PWM, or then it is the same thing that was in the phones that do not have PWM, e.g. other source of flicker like Temporal dithering.