Yeah, it's not a monitor issue, it's a visual acuity issue. I'm quite nearsighted and have a lot of astigmatism, even with glasses, so small text is hard to read, and small text with low contrast is even harder to read.
I can see everything but the 1 in your "contrast test" image. I'm sure if I turned up my monitor brightness, I could see that too, but then normal things are too bright. There's no reason for anything to be that low-contrast if it's meant to be read.
I have the system font scaling set to "Medium (125%)" but Minion doesn't seem to respect that setting... or if it does, then the text must be literally microscopic at 100%.