I wonder to what extent shortages were caused by panic buying due to the scaremongering the tv news was indulging in some days ago. That may be a part of the problem. I was pleased not to experience any problems with my online Tesco shop this week or last other than a complete absence of fresh mushrooms last week but not the end of the world (having said that I shall have major problems next time!). One item substituted which isn’t unusual. I buy all the dog food in bulk direct from the manufacturer - can’t take any chances there!
I do intend to carry on doing the basic shop online - the only supermarket in our nearby market town burned down last summer and I found I much preferred the convenience of doing a basic weekly shop online.
As regards water, we have a water filter fitted and can keep some in the fridge, some at room temperature, in recycled or sports bottles. Unless my tap water, even filtered, tasted vile I wouldn’t consider buying water in plastic bottles - so much plastic waste on our planet - and I most definitely wouldn’t give it to a pet save if it were a medical necessity as with the dog mentioned upthread. And buying multi-packs of the stuff means even more plastic. I appreciate this doesn’t address the fact that some people want sparkling water. Glass bottles perhaps? I remember when holidaying in rural Norfolk, where I now live, back in the late 60s the water came out of the tap brown but cleared within a few seconds and we happily drank it. No such problems now!
I can, from personal experience, vouch for the fact that some cats would almost starve before eating something they don’t like! Very fussy creatures but lovely pets.