Veganism, as practiced, is an arbitrary line drawn just because it feels right.
I'm a vegan for about a year, but I have lately been struggling to argue against the idea that veganism as it is usually practiced is an arbitrary line when I consider the rise of cultivated meat and precision fermentation. Why? Because the same argument for continuing to buy food from non-veganic farms can be used to justify the consumption of animal products that can be lab-grown. Most of these animal foods aren't on the market yet, but a few already are, so this is not just theoretical tech hype, and it is absolutely going to become a very important thing for us to figure out as these products become more popular.
Let's consider the ethical implications of eating field-grown tomatoes vs those of eating a bag of sunchips with whey powder in it. Vegans say a hard no to the chips, despite the fact that the whey powder is just a cheap byproduct, but eat the insect genocide tomatoes. Why? Because whey can't be produced without exploiting animals and tomatoes theoretically can. The mass gassing of insects is excusable as a necessary but unfortunate side effect of agriculture.
Except there's a problem. Whey can and IS being produced in vats by microbes. This is not far-off tech. Vegan whey powder is on the market NOW and you can buy it. On the other hand, tomatoes grown in controlled greenhouses exist and are even more available than field-grown year-round depending on where you live. So, isn't it wrong to eat a field grown tomato? When someone serves pico de gallo at a party, do you ask about where the tomatoes came from? Why not? If we're going to argue that pesticide use isn't morally relevant to our food choices because crops can be veganically produced, then it's on us to avoid crops grown using pesticides when possible and practical, just like we avoid lipstick that was tested on animals. Not doing so is simply being lazy or kicking the can down the road.