Your monitor / browser is misconfigured.

On some machines, maximum contrast is exhausting; on others, reduced contrast is near-invisible. The “exhausting” machines can be configured to reduce contrast, but the “invisible” machines cannot trivially be configured to increase contrast.

That's your opinion. I personally think high contrast colour schemes are great, and use them whenever possible. I even bought a laptop with an OLED screen (XPS 13 9310) to further maximize contrast. I hate it when websites specify light grey text on a dark grey background; I find it so hard to read.

To give you an example of the sort of high contrast user interfaces I like, turn on he dark High Contrast theme in VS Code.