I think one of the challenges is the Huge Hungry Machine that powers so much food production, marketing, formulation, and retail - whose main priority is on profit rather than ensuring good nutrition and/or the health of the consumers of the foods.
As examples - vegan food used to be plant based, largely made from scratch with simple wholefood ingredients, and a few nifty workarounds.
Then ‘veganism’ became popularised, packaged, shrink-wrapped, boxed and labelled. Now there are aisles and aisles of hugely processed frankenstein chemistry experiments on the shelves with a ‘vegan’ label. But I suspect many of them are far from healthy, or good for the environment for that matter.
Plus, look what happened after the Sugar Tax. A piece of regulation intended to be helpful, but previously sugar-sweetened beverages were reformulated to have just enough sugar to stay under the threshold, but then a bucket load of sweeteners.
Did I hear the other day that the UK has one of the highest levels of consumption of industrial ultra-processed hyper-palatable foods in Europe?