Earlier quoted context omitted.
That's an uneeded "optimisation". There is nothing wrong with eating meat and breeding cattle. Again, the issue is that the environment has a limited, finite capacity, which we exceed when we are 10 billion with good standards of living. To reduce quality of life (because it's not limited to meat, it's comprehensive restrictions) simply to accomodate ever more humans on the planet is madness and unsustainable, anyway…
If you think there are too many people, remember that you are people.
Obviously we are all people. The question is do we keep chasing an ever increasing population or do we accept that it cannot keep growing and should in fact probably decrease?
Most developed countries have birth rates below replacement rate so this is already happening. We need to accept it and adapt.