Not all countries have supermarkets in the same way as the uk.
The us is the only place I've been where they have them on the same scale. Supermarkets in Europe and Aus/NZ are much smaller and have much more limited ranges.
They are also less sophisticated in terms of the psychological trips they use to maximise sales.
Markets are much more prevelant elsewhere too. We buy less local fresh produce compared with many other places and we buy much more processed food than other places.
So impacts to the global supply chain from covid, Ukraine and weather will perhaps hit us in different ways and to different degrees. We also have issues with Brexit - more complex paperwork (which checks on has been delayed multiple times) and labour as well as our currently dodgy pound are unique to the uk.
We are much more demanding in terms of the range of products we want too. That makes it harder for supermarkets to keep everything on the shelves to begin with.
I love going to supermarkets in other countries because they give you such a different insight into the country and cultural differences.
I have to say one of the reasons I currently prefer shopping in Aldi is precisely because its smaller and has less of a range. One of the tricks to get you to spend more is simply to get you to stay in the store as long as possible - that's one reason that you don't have a basics section where your milk, bread, eggs are near each other. They are spread out so you have to traipse around... Ikea are the very best example of how this is done!