This has been known for a long time, but I had no idea it was this terrible. LOL
I played a game with 96.5% accuracy (including one "brilliant") and I got a rating of 1500. Hikaru plays a game with ~80% accuracy and it gives him a rating of around 2700 or above. (Granted, the game I played was only 15 moves, but still.)
I thought that was bad, but this is a whole new level.
Chess.com game review presents a "game rating" for the particular game you're reviewing. The description is: "This gives an estimation of a players rating based on a single game".
That is a lie. The estimation is not based on the game, but it's actually most based on the players actual rating playing the game. The same game by a 1500 or a 2500 yield a different "game rating". It is therefore just deceit and the game review either can't or wont produce an accurate estimation only based on the game. It's laughable and deceitful to present it as such. Below an example just how ridiculous it is.
A 1500 could play a full game at 99% and they wont get such a high estimate.