Don't get me wrong - M&S and Sainsburys are very expensive places to shop. But I don't see the quality at Morrisons or Asda or yes, even Aldi as being any worse and the prices are very low. Go to France or Germany and try to compare, I can bet that for your average buyer groceries will be cheaper.
From a very quick search, a litre of milk is 20% cheaper in the UK compared to France, Germany and even Poland.
Food was cheaper. It's not that UK is cheap, it's more that eastern europe has gotten more expensive.
Its true i can't eat steak 4 nights a week as god intended but we manage to scratch cook 3 meals a day for 2 people for £70 a week, £85 with a wine pairing.
If you want to forgo eight different vegetables and four different proteins im sure you can do it for less.
I know too many people complaining "food is expensive" when all they live off is gas mark 6 / 25 mins beige rubbish.