Only that Theranos product was techically impossible. Which makes the whole thing even crazier, nobody did even the slightest due dilligence there. Seems to be par of th cours so, other exhibits are FTX and WeWork.
The crypto-exchange part I have read many times it was profitable. Running an exchange is a profitable endeavour as you just take a cut of all transactions. As long as you control your costs it is a money printer.
The rest of FTX was full of fraud and Alameda was a money sink via unprofitable speculation. Also likely helping laundry money as well via poor KYC.
Running an exchange is a great business though if you have the volume, doesn't matter if it is crypto or futures or stocks.