Meat production is still significantly more resource intense, we are cutting down the rainforest to make more room for feed crops.

You don't need feed crops for meat. Historically people used marginal land where crops don't grow to graze animals. (And there is a lot of marginal land, even with modern fertilizers.)

Anything else makes no economic sense.

A lot of “economic sense” depends on where you draw the boundaries of your externalities.

If you exclude environmental impact, basic human rights, animal welfare, and social stability, a lot of really short-sighted and destructive setups suddenly start to make “economic sense”.

It apparently does make short-term economic sense because we use 6 million km^2 of cropland to feed our animals instead of us directly.

https://ourworldindata.org/global-land-for-agriculture

It does not make sense long-term, but the long-term bill will be paid by someone else, so people today don't care.

Reality is that more than 99 percent of US meat production facilities are factory farms.

If you're talking about chickens or pigs, sure. Cows though are raised in fields and only spend a short time being plumped up on feed lots.

You technically don’t need them if people would consume reasonable amount of animal products, which they don’t. In the actual real world we all live in the vast majority of meat comes from factory farms whose entire existence relies on feed crops and antibiotics abuse.

And feed crops are often from questionable origins.

What about all the foods that require more water / inputs than avocados?

It's a notion of mixed sentiment that in some strange land, one could be slapped for daring avocado toast.

Maybe the water is an excuse.

> But I have no idea how global consumption could be reduced without also causing harm.

One can start by implementing democracy. And no, i don't mean plutocracy, lobbyism or other forms of cortuption.

Reducing consumption and demand doesn't necessarily lead to harm.