Honestly if your 401k is wiped out by "the inevitable crash", having cash on hand is probably not going to save you from whatever you're afraid of. If the line machine stops producing line-go-up entirely, we're going to look back at this post* like the meme of the astronauts watching an asteroid hit the earth and going, "Oh shit, the economy!!!"

*assuming one of us remembers to print it out on nuclear-warfare-resistant stock

Also, if the stock market goes backwards in a major way, well... it does that regularly, and then eventually goes back up. Don't chicken little a lifetime investment if you aren't anywhere near withdrawal age, unless you literally need to eat the money now. In which case, fuck it.

Basically chill and work on building mutually reinforcing connections and support within your community.