This is a tough one. I think the American grading system has broken our brains here. To me, a 7/10 is average. It does some things well and other things poorly, or it's mediocre across the board.
And I follow this logic myself. But just for fun, most places do explain their scale, so it becomes an interesting friction of intent and opinion.
https://corp.ign.com/review-practices
Here, IGN editorially considers it "time well spent", and your read would be a 6 or 5 but their methods. It doesn't help that other places weigh things differently, and it doesn't help that a 3.5 is not necessarily a 7, or 70 is not a 7.
Just to add to your point because I agree with you, I think another critical flaw is no one reads the texts to understand why the conclusion was reached, it's just about scrolling down to the number and then finding the tribalism that works for you thanks to corporate fanboyism and franchise loyalty. We live in a world where people form their opinions off of the previews or prior experiences and want those opinions to be justified in the future, because I don't think modern society can handle criticism or change if it makes them incorrect or susceptible to growth.
Funny anecdote about myself:
Growing up in America under the American school system, as a military brat who moved around, the grading scales constantly shifted for me, but I was quite used to a 92 or 93 and up being A work throughout school. And anything less than a B was... Not rewarded with my parents.
Decades later returning to College to change my career in Canada - decades later as a full ass adult with an army stint, nursing, and adult experiences and problems under my belt - I spent the first year of a program scoring high 80s. And I couldn't understand why none of the work I was doing was A work. Stressed me out. Drove me to try harder. I was just programmed to want that A work. And every time, 80s.
It was not until the conclusion of the first year then I even looked at the grading scale, where I discovered 80 to 100 was A work.
The stress I placed upon myself dissolved.
And I also stopped caring and working as hard because as long as I got an 80, which was almost impossible not to do as long as you hit the rubric, I was getting "an A", and could call myself an A student.
So yeah: Broken my brain, indeed.
