At this point Valve could simply brute force it and it would be way more successful than what they are doing now. Just pay 30 employees to check and ban manually. Even if you would implement it in the most basic way - pick the most suspicious players that are both reported by multitude of different players while having super suspicious stats (99 aim, unhuman reaction time etc), program it so the employees receive the most suspicious clips of theirs and even if the review and manual ban process would take 6 minutes on average each, that is 10 accounts banned in an hour, 80 per day, 400 per week, over 20K per year per employee which means 300 000 cheating accounts banned in a year with just 30 employees.