When I look at these charts both of my monitors are very, very close to being on target.
Here's your avatar loaded into Photoshop.
I'm sure that is not intended to be completely black, but looking at the levels, all the pixels are black or nearly black and it appears black on my monitors, which are correctly adjusted by the measure of the gamma test charts and display all other images that appear on them with a normal, expected appearance. There is some combination of things trying to set gamma on your computer that are creating a viewing environment that is wildly different than what the rest of the world sees.