Yeeeah, it's not going to be environmentally friendly, probably the opposite. In the lab grown meat discussions people seem to forget how incredibly efficient cows are at converting biomass to muscle.

For lab grown meat you'd need a circulation system that can reach all parts of the meat and provide it with enough nutrients, proteins, supplements and all that while also removing by-products such as ammonia that result from chemical processes in the cells.

So you'll end up needing a circulation system, immune system, bones for the meat to not get crushed by it's own weight ideally, recycling system like the liver and logistical system to back everything up, and that's assuming the whole process will be energy efficient.

Adding a brain to it makes essentially gives you all parts of a cow except the cow can largely produce the meat without any oversight and will do all the nutrient differential equations automatically.

We're still decades away from being able to scale this up while being within the same order of magnitude in cost. It's far easier to do a decade of chemistry and biology on textured soy meat to perfectly replicate the flavor, texture and nutrient profile of cow meat. This shouldn't come as a shock since plants are more efficient than animals in creating protein.

I'm personally hoping for genetically modified soy beans that have good amount of the amino acid leucine which is lacking in most plant protein.

Sidenote: We are close to fixing the methane emissions of cows by feeding them a supplement mixed with the feed.