Nah, without going into personal details I haven't taken it but all my family members did and so have a lot of my friends. The long hours of constant study and pressure are real things, vid maker wasn't lying about that.
On the other hand, my parents made me do all sorts of extra study for the exam that I was taking anyway, so it's not even clear that long hours and pressure are halmarks of the Gaokao, but rather of parents who value educational achievement (too much?).