Many animals are smarter than severely mentally-disabled humans, yet we don't torture and eat severely mentally-disabled humans. So it's not about intelligence. It's obviously also not about being able to feel pain, because animals can feel pain.

Do you agree with "Don't do to others what you wouldn't want done to you"?

If yes, would you be okay with genetically modified people who are much smarter and crueler than you, treating you like factory farmers and fishermen treat animals? 1-3 trillion fish are enslaved in torturous factory-farm conditions every year, and together with fishermen torture about 2-6 trillion fish to death annually, usually by slow asphyxiation. Hundreds of billions of land-animals (mostly chickens) are enslaved in torturous conditions every year and slaughtered. About 1% of chickens are boiled alive because it would cost more money to make sure the machines that kill them don't miss that 1%. Dairy cows are repeatedly put on rape racks to be artificially inseminated, because they only give milk after delivering a calf. The calves are removed from their mothers, because the farmers don't want the calves to drink the milk. Would you like to be kept your entire life in torturous conditions? Be tortured to death? You and/or your female family repeatedly artificially inseminated and made to give birth, then have the babies taken away so you and/or your female family's milk can be harvested, eventually killed for hamburger when not yielding enough milk to make a profit?

Cows can be housebroken.

Puppies aren't housebroken and their meat would be very tender.

I only see this happening if lab grown meat takes off in a really big way. Which I'm in favor of, but with how it's been going I'm not so sure.