Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

Same reason vegans hate on omnivores - they’ve taken the high road and the benefits are small while the cost is high.

This "vegans have a superiority complex" take is a thought-terminating cliché ultimately rooted in projection. Since vegans make you feel self-conscious about the unethicality of your carnist tendencies, you divert to accusations of a "superiority complex" when that is just the result of you internally grappling with the cognitive dissonance you have when it comes to funding animal exploitation that you have no proper justification for.

Veganism is a justice movement, and vegans express disdain for non-vegans because they often double down on their oppressive tendencies that keep animals enslaved, exploited, and slaughtered. I don't think I'm superior to you because, just like me, you have the capacity to understand why you shouldn't support the oppression of sentient beings. Not only do you have the capacity to understand it, but you can take that to its logical conclusion and live in a way that is in accordance with said understanding.

Also, the framing is off here. A principled ethical vegan doesn't see veganism as a "benefit;" we see it as a moral obligation and baseline. Saying that veganism comes with "benefits" is like saying that refraining from calling racial minorities ethnic slurs comes with "benefits," when it's actually just basic decency toward BIPOC.