I'm bringing a thought that sounds absurd to you in response to an absurd idea to me that veganism = leftism. It has commonalities but one does not require or imply the other.

I think moral comparisons are arbitrary and differ from person to person, I think there are positive and negative directions that can be aligned or askew between people. I get all the benefits from environment health and societal welfare by choosing plant over animal products, but each person should draw the line where they want initially, then continue to improve where they feel like they can after constructive discussion. Shaming or strawmanning people's choices is not my intent, I'm suggesting how as a society we can further improve and reduce impact from agriculture while still being able to sustain a healthy life for ourselves. The one, single, solitary thing I push back on is the gatekeeping aspect of it from OP.