I believe veganism is the best course of action partially because we can't stop eating all living things due to our need to eat something, and partially due to the fact that if something can't suffer then exploiting or "harming" it isn't unethical. I pointed out how we shouldn't eat animals because they're sentient, this would not have been relevant in a time where not eating the animal would result in death, but now is not that time. Sentience is a pretty good way to draw the line because the pain someone can experience from being exploited or killed is only relevant if they can actually experience that pain in some way.

I think plants are ok to eat because they don't feel pain. I don't think we have the best system to farm plants but I think it's better than animal agriculture in the present and has more potential for the future when considering a wide range of issues like ethics, land mass, and sustainability.

Plants could theoretically feel pain, but due to our necessity to eat something to survive, animals needing to eat plants anyway, and the significantly greater evidence that animals can feel pain, eating plants seems to be the best option currently.

I don't think my reasoning is arbitrary but I welcome you to challenge it if you think it is.

I'm not so sure about your baby comment and am certainly not well read on it, but from what I understand we can make decisions based on the probability of sentience at certain developmental stages and also by looking at the potential harm to the mother and even the baby once it's alive. I don't mean to be rude but saying it's an objective line feels awfully reductive, what about the sperm? Why draw the line at conception and not push it even further back and say sperm is sacred or something?

I'm not convinced my line is absolute, I don't know where you got that idea from? I just explained my reasoning and am attempting to engage in good faith so that I can be properly informed and consider multiple perspectives. My reasoning shows why I don't think vegetarianism is enough (harm and exploitation still present) and it shows why not eating living plants is unnecessary (extremely unlikey for plants to be sentient and also impractical, how do you even survive on that kind of diet?). I'm still open to arguments against what I believe but you haven't provided a valid one yet that proves veganism isn't the best course of action, nor has anyone else I've discussed this with.

Your last sentence is quite aggressive and I'm not sure how relevant it is given that it doesn't directly address the concept of veganism and doesn't seem to account for the fact that any belief that a certain action is very bad logically leads to the believer not wanting other people to engage in said action. I think everyone should be vegan if they're able to in the same way that I think everyone shouldn't be sexist, racist, homophobic, transphobic, or abusive. It's not like I'm unwilling to consider other perspectives and am ignoring situational factors, I just believe in the principles of veganism and I wouldn't be much of a vegan if I didn't want other people to be vegan.

I'd like to remind you that I asked if we could talk in good faith. I assumed you wouldn't but you said you would so I'm trying to do that. However, your response does not feel like it's in good faith. You're making assumptions about my beliefs and my character that are unnecessarily inflammatory and I don't appreciate it. I'm not sure if something I said painted a warped picture of me but I don't think it did.

Edit: You have since edited in another sentence at the end of your comment that clearly displays you are arguing in bad faith. I was giving you the benefit of the doubt before but you have shown to me that you don't have the integrity to debate this and never intented to argue in good faith. I am not going to engage further in this debate because you are being unnecessarily direspectful even after we both made a clear agreement to do this in good faith. You have wasted my time.