Fast food is called “fast food” because it’s fast, not because it’s food.
Apart from that, there is probably no production chain that has profited better from making things the cheaper way than anything related to food.
So this does not just concern fast food, but the HFCS loaded soda you drink, your bread swimming in dough raising and stabilizing chemicals, or your tinned soup made from water, starch, food coloring, flavors, and preservatives.
Just because of the masses produced and sold, any cent saved on a single Burger quickly adds up to a million dollar in extra profits. Don’t expect them to waste that money on better ingredients or flavor, as long as you keep buying that stuff, they keep on making it worse to save yet another cent.
Are you going to tell this to the British expat pensioners in France and Spain? Because they probably never knew that meaning.