Would physical cash help in the event of computer chaos?

It seems like a lot of finance is mitigation and control of risk. What with the Hugging Face etc. and the general feeling of malaise I feel like bank accounts writ large might not be that useful in extremis. Lets say I go to log on to my Vanguard account and it says 404 or shows me a negative balance and all my calls go in a circle with no escape. The ATM smugly eats my bank card the branches are mobbed or closed, credit cards? Hah!

Is physical cash going to be worth much in this scenario? I honestly muse sometimes about puting 25k in small bills under the floor boards or something. I'm not a guns and canned beans type, I believe that in a social collapse, (like wartime Sarajevo,) it is going to be social survival that gets you through not hoarding, (unless you have natural gangster proclivities and even then...)

I'm just wondering if US currency will still be a medium of exchange and store of value or if I should just go long on cigarettes and whisky.

Anyone entertained such thoughts?