Quite a few of those contracts are unused right now, belonging to older variations of Tornado Cash. A whole list of OFAC-sanctioned intelligent contracts that relate to Tornado Cash’s community maintenance are available in Appendix B. Security aside, on the other hand, this may or may not be privacy enhancing. https://stopthepressesdoc.com/how-tornado-cash-enhances-privacy-for-ethereum-and-bnb-transactions/