in fact, Valve did so that all cheaters sit in uncalibrated without prime, which is why players who play cop for more than 100 hours or who have a prime chance of a cheater to appear are minimal.
Cheaters have been breaking the game for years. Anyone who thinks CSGO going free to play flooded the game with cheaters is either new or wasn't paying attention at all. Before prime, especially in 2014-2015, DMG+ was entirely closet cheaters, Silver was full of cheaters on low rank accounts to dick around against bad legits, and GN-MGE was a clusterfuck of HVH. Prime helped for a minute and then cracked prime accounts became widely available for $2-4 and that became hell too.