I always 'follow the money' as 'they' say
to see 'why' things may be being done the way they are being done. When there is profit to be gained with no short term or immediately provable negatives, I tend to question the motives and the 'facts' presented.
A couple years ago when my vet was treating one of my male cats for a urinary blockage, which apparently has a published common cause, he assumed the food the cat was eating was high in a particular ingredient, etc. found in common retail pet food but after seeing what we fed the cat, believed the food was not the cause of the blockage and recommended we not change the food because the ingredients were so clean.
I have never had a cat or dog who would eat Science Diet...not exactly sure why, but after the first several doing that, I just never bought it any more even to see if they would. I read labels, look up, and go by, ingredients...not brand or commercials or vet recommendations...but that's just neurotic me!