> Is tiresome explaining this again and again to people that don't want to understand

I feel the same way.

> Because humans eat a lot of ocean products that fall into omnivore diet and would need to be replaced by soy.

How much seafood? How much soy?

> Because many arid places where you can have cattle are not suitable to culture soy

What percent of all cattle is that? What if only free-range cattle-rearing in already-existing pastureland were allowed to continue, but feedlots and grain-fed cattle were phased out?

> Because vegetables are not enough in very cold places. You really need to eat animal fat there. Lots of it.

Sure. We're basically talking about Siberia, Greenland, northern Finland/Sweden/Norway, and northern Alaska and Canada. Not very many people. They could continue to eat animal fats and it wouldn't make much difference.

> replacing the meadow with a monoculture of soy

Soy isn't the only bean. There are literally dozens of types of beans.

I don't think you realize:

1. How much soy and corn are grown to feed animals

2. How inefficient that is compared to feeding soy and corn to humans