It's also possible that the FDIC might sell the remnants of Silicon Valley Bank to a larger bank that will assume all deposits.
If it was some small bank that was only impacting “regular people”, then probably the government would not do anything.
But that is not the case here. The depositors of SVB are very wealthy and powerful. Also the standard process of selling assets is too slow, and that delay could create a catastrophic domino effect. Famous investors are already calling for the government to fix the issue within 48hrs.
Maybe the government will step in as a temporary lender, letting depositors borrow against their deposits, which they will eventually get back.
SVB is a special case -- a bank focused on commercial customer base.
But above that bucket, people/orgs are expected to know and appropriately manage the risks that they're taking with their money or have the float to pay someone who does.
Experienced money doesn't see large bank deposits as safe by nature because they never have been. It's only people new to wealth and chronically blind to tail risk (hello startup industry!) that assume a $5M portfolio can be treated as casually as their personal checking account.