Everybody runs their lives the way that suits them, whether planning shopping, cleaning or whether you iron everything. No system is wrong or right, good or bad. Every system will have someone who criticises it for some reason or an other
Personally, I have always gone for the big monthly shop; topping up my stocks of everything; food, cleaning maerials etc etc and a weekly shop for perishables and one offs. I have a large chest freezer which needs to be kept full to run efficiently.
I do not consciously plan for Armegeddon, just try to keep time spent shopping to a minimum, but at the same time, while I shop to a meal plan, my shopping is guided by a commitment to environmental principles and I try to both 'think global , act local' and this means using local shops: butcher, baker, farm shop, local market. Once again to save time I buy in bulk; 4 loaves, 6 months supply of meat etc.