Why do supermarkets change something just when it's good?

[faithfulbird20]

Ingredients in food...

Material in products list goes on and on...why change something that's good?

It’s called value engineering. Basically the changes make in cheaper to produce but the selling price remains the same. They hope that customers are so attached to said product they either won’t notice, or won’t care.

There’s people employed in factories who’s entire job is to “value engineer” the products.

It's annoying isn't it?
I experienced this with Shreddies breakfast cereal. I used to like Shreddies because, unlike other cereals at the time, they were not too sweet and had a nice, malty flavour. But the manufacturer suddenly changed the recipe and from then on they were revolting!
I wrote to the manufacturers, who replied saying that the change had been made as a result of focus group feedback.
I think those groups must have been addicted to sugar because Shreddies then became sickly and hypersweet (and, to me, inedible). I stopped buying them and haven't eaten Shreddies for decades now.

My assumption was always that the product became uneconomical.