I hear you. I've tried to rule out as many variables as I could - OLED doesn't seem to cause problems for me, as the Oculus Rift DK2 and HTC Vive don't cause me undue eyestrain, and it's impossible to wear anti-blue glasses in those so it would be VERY noticeable. I've also had a Note 2, Galaxy S7, and Pixel 2 cause no issues (all OLED). I have relentlessly and exhaustively tried almost every possible combination of software settings and monitor calibrations, but I still haven't been able to narrow the issue down to one particular problem area - it's not dithering, anti-blue, PWM, refresh rate, brightness, contrast or gamma related for me. I somewhat recently got another old Samsung 2233RZ for testing, and I can confirm it still gives me zero eyestrain. I also still have the VG278H, and it still gives minor eyestrain, but it feels like sheer relief to look at that one after compared to the PG278QR. The laptop is almost as bad as the PG278QR, by the way.
It's a lot of money, but if you want to remember what it feels like to actually enjoy using your own PC, I recommend you do the same as me - with the disclaimer that you often have a week (or more) to return your new monitor for any reason.
I'm curious to hear if anyone has a true VA panel which doesn't work for them so far. The panel tech still has a lot of room to grow, but it's really not terrible right now. Cheap VA's do have horrendous motion blur, but if someone needs one for work, they do get pretty cheap at the low end. I'm just not sure if this is an isolated case of "lucky model/combination of hardware features works for one person", as some very old TNs and IPS panels didn't bother me, but I'd like to know if there's something to VA's.