If you don't understand the basics of the US banking system then not sure you should be running a business.
Unless you are fully bootstrapped with no major cashflow issues, there are not right answers to this.
The burden is not on small businesses. Most small businesses don't just have well over a quarter million dollars in cash just lying around collecting dust. And the few that do can open an account at second bank. It's not rocket surgery.
Beyond that, if they have the kind of cash flow where they need millions in cash sitting around, they should hire a finance professional. For many, many reasons, bank failure risk being a very small part of it.
Then the CEOs/business owners going that way should fully ascertain and support the associated risks.
Mm hmm. Yes, after all is said and done, the main take away from this is that startup employees and founders no longer deserve credit for taking risks and doing something new. Glad our priorities are straight here on hackernews.