Aren't they still microorganisms at that point? Don't they have hopes and dreams like animals? Or do we not know about either and are drawing a magical line at some point?
No. A randomly arranged amorphous mass of protein is not a drumstick. There is no bone, there is no skin, there is no cartilage, there is no connective tissue.
Would it not make sense to re-use the circulatory, filtration, energy production, digestive, and excretory systems that evolved over millions of years to locomote chicken flesh, rather than try to re-engineer these systems? Just ditch the brain. If there’s no sentience, what is the ethical difference between this and vat-grown synflesh?
https://en.wikipedia.org/wiki/Mike_the_Headless_Chicken