First of all, I think that in addition to regular audits, the criteria for starting centralized exchanges should be tightened to the extent that not everyone who considers himself capable of such a job can open them.
If, for example, someone did a serious check on Sam Bankman, he could very easily conclude that he is not a person who should be given the opportunity to deal with anything related to finance - the man is incapable of uttering two meaningful sentences, and they gave him an opportunity to embezzle billions $.
Therefore, audits should be at least twice a year, and the license to start such a business should be equal to starting a bank.