Anything you'd normally consider to need to be refrigerated though starts from the "when did you open it" sort of consideration though - meat and vegetables both have about a 1 week timer on them in my experience (though you'll usually know by smell in advance). But "smells okay" isn't a chance I'm going to take unless I'm in a survival situation - and you need to buy groceries weekly anyway.
What helps a ton is having a cheap chest freezer though - they're much more efficient on power, and you can store a ton of stuff in there for ages and just defrost as you go.
I don't understand why the idea that an average person gives themselves food poisoning often is rocket science here.
I think most people simply haven't looked into food safety material enough to integrate a probability that they had a food related factor when they feel sick and therefore conclude that they have no food risks in their daily habits that would equate to a small risk of a major health incident in a centralized kitchen, etc.
I hope you don't strictly follow that rule or you'll throw away loads of absolutely edible stuff. Pickles, ketchup, mustard, jams, ... Yoghurt is often still fine after a week. My thing of miso has been open for months.