While it's more ethical for the animal, I must question the carbon footprint and efficient and effective use of resources to make synthetic beef.

Firstly, to make it scale you'll need a lot of machinery. Then you'll need the right nutrients. It will need a lot of technology, because to make beef grow it will need to have everything maintained and provided for it. In nature, beef cattle can be run on reasonably unproductive land (feed lots notwithstanding). Cattle, as it turns out, are very effective and efficient factories of meat production all by themselves.