
My first thought is why are people using these box mixes, the ingredients are trivial. There are recipes online that have the ingredients.
The base ingredients for many things are flour, sugar, baking soda, baking powder and salt. – these are not expensive and are shelf stable. A chocolate cake mix adds cocoa powder. Some need vanilla.
The mix already requires adding rggs and oil.
Mixing it yourself allows way better quality control; they aren’t using high quality cocoa or vanilla.
The levener is baking powder and baking soda. Rhese are cheap ingredients a container of each can last years.
Those mixes are easy to replicate. If the mix changing prevents them from making it from scratch they were never a baker. Anymore than making me making a Mac and cheeses makes me a chef because I added some sliced cheddar.
These mixes were created for convenience. They did mot create the concepts behind the end product. They are made with magical difficult to source ingredients.