I really don't think you can blame Effective Alterism (EA) or these guy for FTX. FTX was a fraud and it occurred because Sam Bankman-Fried used customer money to prop up his failing investment company (Almeada Research). To be blunt he stole from his customers to try and prop up a failing business. He also lied, used customer money to fund a lavish lifestyle, used customer money to donate to political causes, etc.

Basically, I doubt Effective Altruism condoned stealing from people to prop up businesses, fund personal causes, and enrich oneself.