Change your browser settings. You can tell the browser what font you prefer to use, and set minimum font sizes. You can also turn off remote fonts, so that pages can only use fonts you already have. Then you can just uninstall any fonts you don’t like or that you cannot read easily.

Huh... Guess it's what you're used to.

First thing that struck me about the site is how beautiful I found it. I even inspected the font: Iosevka Web, apparently.

I'm surprised you say that. Iosevka is quite beloved as a monospace font. I use it for all my terminals, etc.

Prose in monospace is harder to read regardless of the specific font.