One pretty consistent moral among societies is that needlessly causing harm is considered wrong. Outside of lab grown, its impossible to acquire meat without grievously harming an animal. Further, the vast majority of our meat is NOT gained by hunting but instead by factory, and the conditions of meat factories are appalling and horrific. So yes, if we CAN get the nutrients we need without the consumption of meat, that is the most moral way to get our nutrition met. All that being said, even today, being able to meet all nutritional needs without any form of animal cruelty is an incredibly privileged position to be in, and we arent quite at the stage where its fair to judge others for not doing so

(edit: and I say this as a meat eater, meat is fuckin delicious and I dont want to give it up. I'm personally banking on lab grown meat becoming an economical option, at which point we have removed the ethical muddiness of it)

(Edit 2: Lmao, I ruffled the feathers of a lot of meat eaters who've likely never actually had to kill any if the animals they've eaten. I have, I still eat meat. Reality is messy, fucking own it)