The environmental destruction wrought by gigantic, inhumanely scaled monocrop farming is direct, immediate, obvious, and worthy of huge mobilization to resolve.
Instead, we hear, as you say here, that if the carbon emissions are low, it's Great For The Environment!
And what do you think the animals are fed with?
If you're going to have 8 billion people eating meat do you really think there's going to be less environmental impact growing the food for the animals + the impact of the animals themselves compared to just growing vegetables?
I feel like meat scales even worse due to efficiency losses
My cows are fed exclusively grass, right to finishing.
My pigs and chickens are fed mixes of locally-sourced corn, oats, barley, peas, and lentils from organic growers. And they supplement with grasses and broadleafs because we raise 'em on pasture.
Well-raised, environmentally reasonably-fed animals cost lots of money.
Meat is basically the healthiest thing people can eat.
If you just take the pasture-raised cows alone, the grass grows itself and large herbivores are a natural part of the environment here--the environment and its polyculture would be harmed by their removal.
I hope it will outcompete cheap, monoculture-soy fed, medicine pumped, densely grown and factory slaughtered cheap meat.
The second is far more common than the first. As you said, good meat from well-raised animals is expensive.
So not the awesome and expensive steak you may eat from time to time, but the cheap meat in fast-food, the chicken-wings, burgers, lasagnas, pizzas, tacos, currys and more.
Soy and corn is mostly grown in the Midwest, using aquifer water that is being rapidly and permanently depleted. Not only is monocropping as a strategy for feeding the nation unwise on its face, but it will ultimately lead to food insecurity In 30-50 years as desertification of the Midwest starts to be a thing.
The monocrops you mention as a problem are largely used to feed cattle today: about 80% of land used for agriculture produces feed for livestock, most of it single crops like corn and soy – despite only contributing to about a fifth of the calories we consume. And it's not like we can greatly expand production either, we already use about half of all habitable land for agriculture.
The tail wags the dog in the thinking here. “Scaling” fast food price hamburgers is the problem.
It’s a problem on a bunch of levels. It’s not scalable because we’ve changed the definition of food. The best farmland in the world lay fallow because we’ve committed to growing vegetables in the desert and raising ruminants in pens, because it’s more efficient to the small cartels of processors who drive the status quo.