That is exactly the problem.
It's too convenient to buy the plastic wrapped poor quality stuff, so the supermarkets will keep selling it.
It's a real battle when consumers have the power to make positive changes, but not if it's inconvenient.
There are stalls in East D, Peckham, Brixton and Herne Hill that sell fresh fruit and veg, not wrapped in plastic. You don't have to look far at all.
The argument for being too busy is not convincing. It's really just an excuse.