I mean, the reason of the SAT's existence is the convenience of boiling down one's entire academic experience into one number. Perhaps the real problem is that university admissions allow the dualopoly of College Board and ACT control the academic fates of the nation's students with no public accountability.
When a university makes that decision, that is the student pool they are going to bring in and they take the risk with their graduation stats, employment stats and failure rates.
When college board does it, they have literally zero skin in the game. They bill both the prospective student and the institution, produce this arbitrary number and there is no penalty for getting it wrong since they can just move the goalposts and declare success.
Set a standard (SAT score, whatever) and say that students who meet that standard should be capable enough to admit. Then pick randomly from among the applicants who meet your standard. Sounds fair, right?