The part that the right wing preppers miss the most is community. They are completely convinced they will have to murder their neighbors lest they come to steal their food or become feral beasts. I'd say the biggest prep you should do as a leftist is form a good working relationship and mutual aid network with your neighbors. I know this can be testy or downright dangerous in very red areas, but at least try to have a local group if not your literal neighbors. There's no real way to actually survive SHTF without other people. Even if you had all the food and water in the world, once your break your leg or get seriously ill, you're dead if you're alone. The hyper-individualistic image of a lone survivor keeping to themselves innawoods isn't very grounded. Society never actually collapses except in highly atomized areas. People had towns and cities long before there was ever running water or electricity. Society only collapses when you refuse to form a society.