FDIC won’t go broke, it has a $100 billion line of credit with the Treasury.
But ok, lets play along, no banks.
Why not bond funds or money markets? No? Can’t have your money in them because America is going under? But you have a bunch of US DOLLARS stuffed in your mattress.. makes sense to me.
If you are really that paranoid about everything going to hell then the only things you should be buying is guns, ammo, MREs and a farm with good fields of fire and its own well.