Crypto mixers are mainly used for privacy as stolen funds account for 8% of all funds sent to crypto mixers, according to Chainalysis
Source: https://cointelegraph.com/news/only-8-of-mixed-crypto-coins-tied-to-illicit-activity-report
Only 8% of Mixed Crypto Coins Tied to Illicit Activity: Report
August 27, 2019
CoinTelegraph