My vision isn’t great and I do find it more difficult to read comfortably than most sites. I haven’t checked the actual contrast ratio, but for this particular font and size the text color feels like it’s lacking strong contrast against the background. The tabs at the top are even more difficult to read comfortably than.

But I understand that sites that look this way are not made for maximum legibility, but as an in-group signifier.

The text flows over the whole width is one point, the paddings and margins is another one. Sure, you can read this if you really want, but it's painful.