asus389 I have a feeling we are extremely similar in terms of experiences with some variations. I do have an OLED iPhone X with no issues. I refuse to update to iOS 15. (I'm on 14.7.1) I did so with my old 10.5 iPad Pro and now I can't use it anymore. Every time I've been in the Apple store in the last couple of years roughly (I stopped going), I couldn't look at any of their iPads, MacBooks, or iPhones for long as I felt very off.
I have a 2017 15" MacBook Pro. All seemed ok for me until I updated to Monterey. I thought it was my anxiety, but sure enough, things seemed "off". I am able to use it, but it isn't my favorite screen. I had to check again, but regarding my iPad, ipadOS 14.7 was my last eye/brain stable operating system.
Tin foil hat time. I think that if they didn't add temporal dithering all at once, they have been slowly dosing us with it over updates. I hope to quantify this once I get all of the tools I need.