At least for the public at large such methods aren't practical (not enough space to raise enough meat) and not able to produce meat at a cost the general public could afford.

It's also still horrible to butcher the animals, I don't consider any such killing to be humane. They are also killed at a rather young age, barely even adult just max size. You also have the forced pregnancy of the animals and odds are the pigs are still crated after giving birth, the cow calves separated from their mothers, etc.