>You can skip all kinds of unwanted growth and a life cycle normal animals have to undergo if you specifically focus on muscle tissue and other parts we actually want to eat and grow it as rapidly as possible.

Thats not how it works. Not one single cell works on its own. In the lab we go around this by pumping insane amounts of chemicals into the medium they grow in and change that medium regularly.

To do what you are talking about and grow a specialized cell in a isolated environment means you need to go back a few steps to feed it.

For example. Feeding a cow requires having cattle feed. This means having a few plant crops that you can grind into meal and feed the cows with. (Lets just ignore for a second that you usually dont even need that, because most of the time they can graze grass from fields that cant grow agri crops).
Growing cells requires medium. To make medium you need amino acids, several minerals, vitamins, glucose, pH buffers, pyruvate, sodium... the list goes on. Not to mention ultra pure water.

To make just sodium pyruvate, one of the parts of this list, you need to make giant fermentation broths where sugars are metabolized by genetically altered microbes to produce a liquid which is then extracted using vast amounts of organic solvents at high temperatures. This sugar is produced by a crop you need to sow, the organic molecules by oil refining and more chemical processes that use vast amounts of energy and other chemicals. All of these chemicals and electrical energy cost the ecology.
THIS IS JUST FOR ONE PURE CHEMICAL FROM THE LIST.

Now imagine this for +20 other chemicals, which all NEED to be pure otherwise your cells wont grow. And compare this with just having two crops and a grassy hill to grow a cow.

What's that? Cows also need a lot of water and electricity, not just food?

Youre right!

Cultured meat need a sterile environment, extremely well controlled conditions and tons upon tons of really pure water. Im not even talking simple destilation. It needs to be completely deionized and filtered.

Can you imagine the energy needed to keep a vat of 100's of liters of liquid always heated to 37°C? Its a lot.

You should go to a local lab and ask someone to show you how a cell culture is made.