I'm late 50s, so over the years have realised you have a back up if the most obviously infrastructure fails.
2007 floods, you couldn't leave your home without getting soaked, water was everywhere on the ground and above. Having clothes you can easily wade through water in are worth keeping.
During the floods, we lost our water for two weeks due to water works beng flooded. I didn't know about panic buying, but got to the supermarket that afternoon to find it was basically empty - everything that didn't need cooking/easy just to open and eat, canned veggies with liquid had gone and drinks had all gone. Bottled water didn't kick in until the next day, massive queue and you could only have four bottles at a time - I wanted some for my Mum and we ended up sharing ours with her until the next day.
We've had quite a few power cuts over the years, if it really bothers you you can't have a hot drink/some soup, make sure you've got a mini gas cooker.
More so in recent times, but panic buying seems to have got worse, especially toilet rolls. I always make sure I've got a few essentials in, so we've got a back up or at least something that would be ok as an alternative. Won't totally help climate crisis, but if you can't get the fresh veg or fruit you wanted, if you've got a tin of fruit, peas or carrots, at least you've got something.
Matches, candles, torches I'd expect most people to have, but maybe not.
I have to admit, we haven't got loads, but it's enough to save us doing a panic buy for some bread (in freezer), toilet rolls, milk (always have long life in case goes off) - therefore, we're not putting immediate pressure on ourselves and the supermarkets.