Seriously though, the box the burger patties come in states 100% beef. No mention of what percentage is meat, but it all came from somewhere on the cow.
Remember back in 2020 when beef got so expensive? The texture of those patties changed a bit for a few months. Usually the consistency is more like integument and gristle. For those few months it was a lot more like the inside layer of skin.
But it was legit still 100% beef.