It's really just the font I hate. In the past I've used Reader Mode in Firefox to make it readable, but just now I went into Ublock Origin to change the font to something I like, using the suggestions from this Reddit thread: https://www.reddit.com/r/uBlockOrigin/comments/r4gzzl/how_do...

  pluralistic.net##*:style(font-family: Fira Sans !important)

If you like your default browser font, you could instead just unset it:

  pluralistic.net##*:style(font-family: unset !important)