Sound financial advice would be having an emergency fund of several months of expenses. You're doing it wrong.
It's 2022. It's trivially easy to convert investments into cash.
Of course that's assuming you're able to sell your stock and transfer the funds in a timely fashion. Maybe things have changed in 2022, but I know plenty of people (especially using Robinhood as their brokerage) who had liquidity issues when trying to sell shares in 2021.
If your emergency funds are 100% stock market instead of diversified investments you're doing it wrong.
If you don't trust electronic systems to stay on-line in a crash then your hedge is probably not USD but other assets, like canned goods / water filter / ammo / hard assets in your personal custody.