Is cat food a scam?

A few weeks ago, while trying to understand cat nutrition in relation to cat diseases, I started paying more attention to cat food composition.

To make a long story short, I was shocked by the composition of canned food in particular, whether it was by reputable brands, or not.

On the left side, the can is from a big brand in pet food, and it says: Water 81.5%, protein 8.5%, fatty ubstances 5.5%, crude ash (!) 3%

On the right side is a generic can from a local supermarket chain. Similar composition: Water 80%, protein 8%, fatty substances 6%, crude ash (!) 3%

So what I'm buying is essentially 85% water and ...ash.

Can the cat sustain itself with the 8% protein and 6% fats? No! That's why it wants more, all the time.

You think you've fed the cat but it's starving really - since what you fed it is not actual meat, fish, etc...naturally it wants more and more as the food does nothing to actually feed it.

As for the ash, I don't even know why this stuff is in there but I suspect it's to create the "stable" look of "gelatinous meat". Or gelatinous water with hints of meat. But why would I even want to feed ashes to my cat?

I don't like this at all - from any angle. Either as a consumer, or a pet owner. Based on the large label, you think you are actually buying some flavor of meat or fish - but this ends up only in trace amounts (which you find out only if you read the small letters).