Honestly, this has to be one of the most non-intellectual posts in the entire history of the forum Bear. I should know, I've made many of them!
A mere glance will tell you that they are per game, minutes played, or % stats.
I think you are being fooled by the ratings being calculated in real time, and are "cumulative" in that sense, but the word cumulative means they can go up or down. It doesn't mean that they are just a running total from a calculative perspective and can only go up. You have to realize that whoscored ratings do go down if a player has a bad performance?
How is Aubamayang at the top side of it after 7 games? How is Mkhi so high after 5, plus two sub appearances?
You can't be taken seriously if you are going to post this sort of thing. The whole point of the ratings are to attempt to provide an objective view of performance. I haven't chosen any particular stats. This is the one overall total performance statistic that is available.
Your entire post is nonsense.