It’s not “some trim”, it’s basically half the animal. I buy several whole cows a year and out of a carcass that yields 400 lbs of meat, I’ve never managed to get more than 60% with a very good butcher. Cabeza/lingua/tripa/offal/oxtails aren’t going to get few more than a few percent points extra. Once you’re deciding on which cuts you want, that trim is unavoidable.

It’s definitely better to freeze the left over bits and grind it yourself, but half the animal gets ground up regardless.