YANBU. People should always have the essentials to survive for a week, longer preferably. Water/food/cash are essential. In winter you need some form of heating and cooking, even a shit-ton of tealight candles will suffice at a pinch. (You can boil enough water for a cup of coffee by heating it over three tealight candles for about 20 minutes in my experience.)
Anything that could go wrong will go wrong at some point. Cybercrime is a relatively recent addition to the list of potential disasters but the list is a long one - war, earthquake, rioting, terrorist attack, flooding, high winds, pandemic, nuclear disaster, meteorite strike to name a handful. Any of these could occur without warning at any time. You only have to look at the early days of the Covid pandemic to remember how quickly supply chains fall apart and how long it takes to restore them (and that's a pandemic where people were actively trying to restore them - in some disasters they may be nobody even attempting to for a long while).
Even in less extreme scenarios there is a genuine risk that millions could be without power, gas and/or running water for a week or more. It's a good idea to really think through how you would survive if these essential services suddenly got interrupted. It's not being pessimistic, it's being realistic and proactively ensuring your family will be in as good a situation as possible if it does happen.
On a much more minor level, imagine the inconvenience if the internet was down for the whole country for a couple of weeks. Could happen, will happen at some point. Make sure you have all your important documents, photographs and maybe a few films saved on a hard drive at home, because you never know when access will disappear. A good example is the Internet Archive going offline for a few weeks last year - many people were shocked because it made them realise how much they used the services it provides. That was a minor (in the grand scheme of things) cyber attack that I don't believe resulted in any data loss. But the point is, everything stored on the cloud may disappear at any moment, temporarily or permanently. Don't leave your whole digital life at the mercy of cyberattacks.