[nzp]

Because it's even more ridiculous than raising normal animals for food. Producing a whole animal minus a functional brain is no less wasteful than raising a normal animal and you have the added expense of developing this tech (which, granted, goes to zero with time). We can already grow meat without actual animals, just using animal cells, and even engineering meat from completely plant tissue is viable. And that's for the case someone is psychologically “desperate” for meat as such, because we don't really need any animal products in our diet.

[wjbdvkjwbbvwdjk]

it is. it's a stupid idea.

although, when I go vegan, I don't like taking supplements. If we could engineer some foods to provide all the B12, Zinc & Iron etc we need that are hard to get from vegetables (without a a lot of effort) that would be nice.

[nzp]

We already do that, kind of, again in an extremely wasteful manner. Farmed animals get their B12 from supplementation mostly, so pretty much both vegans and non-vegans get it from supplementation. The food in the supply chain for both humans and farmed animals is just way to clean (good!) to get enough B12 without supplementation. I'm guessing that B12 is not the only micronutrient that is supplemented. But seriously, apart from B12, if one has any semblance of a reasonable, moderately varied diet, micros are not an issue in a vegan diet, you can easily verify this on nutrition trackers. And if you don't you probably should take some supplementation anyway.