You probably still don’t have to worry: cash in a bank is insured up to $250k per ownership category by the FDIC. Even your (traditional) investments are protected against by the SIPC in case your broker goes out of business.
If your crypto exchange goes away, you, of course, just lose everything.
If your bank is having liquidity issues then it’s long past time to get your needed money out. FDIC insurance paybacks can take months or more to happen.
But! The FDIC is not just insurance. It’s also a framework for risk management including liquidity risk. Banks have pretty detailed playbooks on how to manage liquidity risk that are routinely audited. It is therefore pretty rare for any US bank to have such issues and when they do it’s because they were cooking the books.
Reading through those I couldn’t actually find any banks that had evidence of liquidity issues. And the longest I saw for the fdic to get depositors access to their funds was the weekend.
Most of them don’t even tap FDIC insurance they just hand the depositors over to a different bank.
You actually own the assets at your broker. Only case is if they are lending it for short positions though most brokers let you opt out of that. Also most brokers store money in the sweep account on brokered deposit accounts that are FDIC insured. There’s lots of protections being regulated.
Crypto reinvented the entire banking system, they're just called exchanges now. It's sad that the projects that were meant to put an end to all that ended up making the same mistakes.
For reference, if you ever see a bank say this, it's probably a good idea to get to an ATM post-haste and withdrawal as much as you possible can.