FTX was incredibly profitable, and their main competitor Binance is today a money printing machine. FTX failed because of fraud and embezzlement, not because their core business was failing.
FTX itself was profitable, but that's because Alameda Research was selling dollars for 80 cents, and all the other traders were paying FTX fees to rip off Alameda. Unfortunately, Alameda was running on FTX customer money.
