Hello, 'developing world' here.
I'm an expat doing a rather well paid professional job, so very cushioned & in a position to buy whatever I like. Sometimes we can't buy stuff, especially imported stuff, because there are mysterious supply issues.
But generally, if you earn more than 95% of the population, sure, you can have tonic water or heinz beans, but you'll pay 3 times what you would in Europe.
If you can't or don't want to shell out, you'll certainly not go hungry, because the country I live in is self supporting in terms of agriculture. No problems with vegetables, or meat if you know what to do with a scrawny boiling fowl or a chunk of goat.
The uk is not self supporting. It relies in imports of, well, almost everything.
So you guys have a double whammy - shortages of the luxury imported 'nice to have' stuff, which you've come to rely on, & bugger all infrastructure to feed the country on home grown food.
This was not a brilliant move.