I agree. UK food is cheap. Too cheap. Worryingly cheap (supermarket chicken?). And has been for years. But when an essential commodity like food goes up in price, those with no margin in their household budget will feel the pain severely. Plus, as you say, all the other pressures (crap wages, higher energy costs, expensive housing).
The percentage of our household budget that was freed up by cheap food perhaps went into inflating property prices (including rents) and consumer goods. And, usefully, cheap food for the masses means that employers can pay lower wages. ( "Wage rise!!?....look how much pasta you can buy with your minimum wage!" ).
Mrs T's violent crusade to destroy our manufacturing and industrial sector (where a unionised workforce earned a decent wage) and replace it with service industries (where a non-unionised, part-time, zero-hours, insecure labour-pool earns minimum wage) was a race to the bottom. And here we are.