Most good quality (and certainly the more natural) dry food now is in fact wheat free, unless you're buying at the cheap end of the market.

If you're buying wet food then you're basically paying top whack for water. Most of the meat in wet foods is reformed from the same source as the meat meal that's used in dry food. The meat proteins are cooked up with whatever it takes to get them looking like luncheon meat and then chopped up into pieces (traditionally this was done with soya isolates or polyphosphates). You don't see the ingredients used to do this listed because the regulations don't require it if the chunks are added as a separate ingredient, they are classified as 'processing aids'

So I wouldn't be too keen on championing chunky meat in gravy wet foods - they're a lot more high tech than they look......... but then so are the equivalent human foods (and I speak as a former food technologist!)