For example, Coinbase was founded in 2012 and is still doing well to this day, so not every exchange is going down.
Maybe not yet, they waiting us off guard.
That's such a paranoid outlook although I can share the sentiment, I won't worry too much about my bitcoin lest it's in the whole number or 0.1 territory about the security, probably don't use obscure exchanges and online wallets to store your coins.