OP has a good point. Inflation has made 7 average in trends, but not in all people's minds.
People arguing over what some non-scientific number means gives me similar chuckles to that of when folks argue over pronunciation of a word written in roman characters, by presenting their own set of roman characters that somehow are supposed to give a more clear and less subjective reading.
(See that Shenmue thread.)
It makes sense for the middle of the scale to be average. But due to inflation it isn't. Thus the scale is wonky and not useful for describing how good something is, but rather is skewed to have many degrees of how bad something is. And that's not even something folks are interested in, as nobody* wants bad games in the first place.
Furthermore, just as any two of y'all in this thread probably have a different take on what exactly a 7 means, so does basically every game reviewer, which makes an average/aggregate of their collective near-7s virtually meaningless, as the numbers weren't measure the exact same scientific value each time.
Numbers just make us drop our guard and almost assume some sense of objectivity is in order. I mean, numbers are usually objective, and represent many reproducible scientific values.
Thus, the question shouldn't be what does a 7/10 or 70 on metacritic mean for a game (aside from possible missed bonuses from the publisher, because that's still a thing), but instead what does a 7 mean to each individual that's reviewing said game.
The solution?
Read the reviews.
It doesn't take long, and you'll know significantly more than if you just look at some number and assume what it means.
You'll also have less arguments with strangers about whether that number was correct or not, because you'll realize that it has to be correct. It reflects whatever opinion the person who assigned it has, and they're the foremost expert on their own opinion!
Reactions and observations on video games will have objective facts noted in them, but they will mostly contain subjective insights, which can have a ton more nuance than a 10 point or even 100 point scale.
Then, when you read your another review with possible a different number at the end, you can see what that number actually means, without any confusion as to who was right, because they both were!
It's a fantastic life choice. Don't sleep on it.
But what about Metacritic?
Use it! It's a handy quick list of a bunch of reviews that you can read!
Do you review games also?
Maybe don't include a number. Folks might just be scrolling down to see some otherwise meaningless number if you include one. If you don't, they'll either actually read it, or they won't, which they were trying not to do anyway by seeking out some holy number.
If you already don't include numbers, kudos to you! You've already dodged some bullets by doing so, because you can never give a game the "wrong" score if you never give it a score in the first place.
In conclusion, Jim Sterling was objectively wrong about Breath of the Wild. It was not a "7/10". It was most definitely an 8.8. I have a game thermometer that can objectively sense that stuff, and I can tell that Jim is making things up like it's just his opinion or something.
(*okay, so, some people actually enjoy bad games on purpose)