How much of the beef that humans eat could be grown that way? Answer: less than 5%.
Also: and how are we doing 5000 years later? Well, we've killed almost all of the wild mammals and replaced them by meat.
See those tiny green dots? That's all that's left of the wild mammals. Actually, that comic is 7 years old, so one of those green dots has gone gray.
Everyone claims to not want to destroy the climate, but when it comes to giving up anything specific, anything at all, there's always a reason why we can't give it up, not nohow. Think of the jobs lost, we can't do that!
So don't worry - you're going to win this one, for sure! Those pathetic people who want a livable planet for the future will definitely fail, because no one's going to give up anything! Everyone will keep eating meat, keep driving cars, flying all over the world, and, like you, emitting a pack of excuses and hostility whenever challenged, just like they have my whole life.
Sure, it sucks for all humans for the rest of time, and those millions of non-human species we are in the process of wiping out, but you sure showed the future that no one could tell you what to do, and that's the main thing, right?