I really enjoyed the question, “Is this sustainable for humanity?” Thank you for sharing it.
I wonder if it is necessary to ask, answer and then arbitrarily restrict oneself accordingly to one extreme.
For example, you question if it’s sustainable for everyone to eat meat. But in reality, it’s a matter of preference among humanity: some people enjoy eating meat, some people don’t.
Certainly, if everyone ate the same amount of meat as the eager meat-eaters — that would be impossible to sustain. But it would be sustainable for everyone to eat a little meat at regular intervals. And there will be fluctuations from that equilibrium, as some people don’t eat meat, and some people are eager to.
Hopefully we can find a way to discover the right balance.