You’re right. If farm animals were sedated before being killed, it would certainly be preferable, but wouldn’t make it right.
We have no right to cause pain, fear or death to sentient beings, purely for ~15 minutes or pleasure. Doing so is immoral. There is no valid argument against this. Trust me, I did NOT want to be a vegan. I argued against it for four years trying not to become one. But there was and is no argument against it. Eating meat is immoral, bad for the planet, bad for the animals, bad for modern medicine, and in a typical western diet, bad for your health.
I repeat, there is no argument against veganism, and being vegan is objectively he correct moral choice.