There is a causal relationship (rather than pure happenstance) because colleges ask for them and tell us they put weight on them (although GPAs/scores are not the overriding factors) and the correlation is meaningful as (using the above headline) 35% of perfect scorers are admitted (versus, say, 5%).
So, there is some predictive value - similar to the GPA/LSAT tables for law school admissions (see UGPA/LSAT Search Results (lsac.org)) - even though law schools consider other factors as well.
I am repeating myself a lot so I think I will stop here. Have a nice day, everyone!