I agree with you. I stopped feeding all my pets commercial pet food a long time ago, after working in a pet store and researching the ingredients and cooking processes of the pet food brands. If people could see what went into the animal food they buy they would be disgusted. Also the processing of the food is harmful to what little nutrients remain in the processed food, so manufacturers have to add chemicals and preservatives, salt and other stuff.
Then they market the brands with crazy claims about prolonging beloved pets lives, and dental care, and prevents illnesses etc etc, and these claims are simply not true, or are, at best, vague in their wording to mislead consumers.
Many people are now at the point when they are feeding their pets nothing more than dry hight temperature baked crusty corn waste, with some undesirable animal bi products that are not fit for human consumption, all mixed together with additives, preservatives and colouring.
No wonder now so many pets, like dogs and cats, are overweight, have skin allergies and digestive problem and the worst dental health since time began!
Now I feed my dog human grade meat, with bones and internal organs included. I feed my pet birds a good quality seed mix (no coloured flavoured corn pellets), fresh vegetables and fruit, organic calcium sources such as cuttle bone and egg shells. Since stopping the artificial diets all my pets are much more healthy, and my dogs bad teeth have totally cleared up.
I am now in the process of changing my own diet to cut out processed foods after seeing the effect they have on animals.
I now think most dry pet foods are simply easy ways for counties to get rid of their grain surplus and bi products from the food industry.