You're talking about mostly the folks on All-In podcast. Good show, but they are very emotional right now as this is hitting them right in the gut. If nothing else happens (no other bank runs), things in the Valley will be dreary but not extinction-level like they say, but here are some facts:
1. FDIC already announced all depositors are getting 50% of their money on Monday. Then they will get 80-90% of the rest of their money over some time. Probably pretty quick, a few weeks. They have paperwork all stating this.
2. Some companies were very stupid literally had all their cash in one single bank, well over the FDIC insurance amount. That is a colossal mistake. Some may have just did it out of ignorance, or out of laziness, or because SVB was offering great perks. Either way, there is a cost to great perks, it's called risk. Any company could've avoided this situation by simply keeping its cash needs in a diversified way, which corporate treasuries have been taught to do and have been doing forever.
3. Even if a company had all their cash in SVB (very dumb), they are getting 50% of it back Monday. If they can't operate on 50% of their cash they were doomed to fail anyway. OR, if they have such a great product, some investor will come in and give them a loan to cover the short term needs, especially because they have a certificate from the FDIC proving they have funds but it'll just take some time to get.
So yes, these VC types are freaking out because in general folks will wake up to how overvalued some of these companies probably were. But the idea of millions getting laid off just won't happen.
HOWEVER, all of what I just stated assumes there are no other bank runs. If there are other banks runs, all bets are off and no one knows what will happen.