If your screen setting make the black on white / white on black way too intense to the eyes.
Shouldn't people adjust their screen to match their need?
Why on the earth a website lower its own contrast because it expect everyone using a over contrast screen.
It basically make the site unreadable for everyone that has a sane setting.
Unrelated fun idea for hardware engineers: develop a GPU that outputs average image brightness before each scanout. This allows the monitor (or GPU itself, though you'd suffer quantization issues) to slowly ramp during dark-to-bright transitions. Consumers would love the feature: people like to stare at devices in dark rooms (bed etc) but melt their eyeballs every time they navigate from a dark page to a light one. This would prevent that pain.
I think that is why hdr invented at first place. Sdr is never meant to present "sun casting on you directly". The sdr #fff in hdr setting is called "paper white". Looking at paper shouldn't hurt your eye in reality and nor does on screen.