I think it's an issue of animal husbandry rather than are we allowed to eat meat. After the flood, it was sanctioned by God.
And also, if there are too many animals and we are starving, of course we do need to eat some meat for survival. We can eat fish too, which is the preferred diet of many people.
Some cultures even eat insects as their protein. For the Israelites, the animals needed to be slaughtered in a kosher way..something to do with bleeding though I am not a butcher. There's a special way it is done.
Home kill is a lot more humane than rounding up animals for a trip to the abbattoir. But then it's the scale of the enterprise, when people live in cities of course they can't farm the land at the same time and need their food imported in, ready made. Its the same with mass manufacturing of goods. How much of all the stuff we use is made in a factory. I would say most of it...I didn't make this computer myself or assemble it, I didn't make the clothes I am wearing, and the house was built from a kit set.