Somehow we would need to agree on some commonalities on the problem. To get any momentum for a class action or any kind of group complaint, there would need to be at least of one source of the problem that we are trying to fix.
I see a lot of different problems here, like it is completely individual for each person what is the source of irritation. After having this problem more than 25 years, I personally find it hard that I would be a unique individual with my problem and I think the same goes for any company.
For me, I've always had the problem with flicker, be it PWM or dithering related. It is only the flicker. If a display does not flicker, then I do not get eye strain. I have countless of devices that I have tried over the years and always find that if there is PWM like in OLED's or LCD's with PWM controlled brightness, my eyes get red. I have no other symptoms like headache or nausea. Just irritated red eyes, and they get red after 15-30 minutes when using a PWM screen.
More recently on high end devices like Macs and Surface devices, they utilize the dithering which is a way to flicker the pixels to show more colors than the panel can natively display. This is another source of eye strain, but it is more tolerable than PWM. But still I cannot use a laptop at work with the dithering.
Luckily there still are devices like the Motorola 5G Plus phone and some laptops that yes, do have PWM, but when at higher brightness, the PWM is not activated, so they cause no eye strain whatsoever.
But as there are people who report eye strain with different versions of Android and Windows as well as looking at a grey color or something else like that, it will be very difficult to gain momentum, as this whole problem just looks so weird from an outsiders perspective. I if we are not able to pinpoint what actually causes the problem for most people, then most people will not get any solution. Companies are not going to fix a problem that is related to different versions, grey color, or PWM being OK sometimes but sometimes not.