I don’t know what you’re suggesting here really but in general running an exchange seems like a reasonable looking business – you match someone who wants to buy with someone who wants to sell and collect a tiny fee – and FTX appeared to be well run and profitable. The risks would mostly be getting hacked, massively (unintentionally) screwing up the accounting or being outcompeted. I don’t think one could have easily predicted this from first principles and if you’d told me a year or 5 months ago that one of the big N exchanges would blow up before 2023, I wouldn’t have guessed FTX.