Veganism isn't better for the environment than significantly reducing the total amount of consumed meat. Animals play an important, difficult-to-replace role in making agriculture sustainable. Animals can be herded on land that's difficult to farm on, animals can consume parts of farmed plants that humans cannot, and animals produce products that humans cannot replicate without significantly more work.
Edit: I see a bunch of vegans who aren't really engaging with the argument. To be clear, anyone who makes statements about how things are right now to try to disprove this is probably arguing in bad faith. I'm not responding to comments anymore because, while it's entirely possible that I'm wrong, y'all aren't making any good points.
Furthermore, I'm not anti-vegan, but now I'm tempted to be. So many people I've engaged with have displayed all of the worst vegan stereotypes I've heard about. I've always assumed it was chuds making shit up, but no I just hadn't met any of the terminally online creeps in the vegan community yet OMFG.