Unless you debunk all the arguments then veganism is unfounded and incorrect.
Veganism is the default under any reasonable moral system. Carnists come up with unusual new arguments as to why it's ok to betray this moral default, like this one. In fact, one can programmatically generate an infinite number of new anti-vegan arguments, e.g. "Veganism hurts our ability to manufacture X", wherein one can simply slot in any market product, e.g. anything from full-size foosball tables to action movies with helicopters in them, and no matter how tenuous the link or asinine the product, it still technically represents an undebunked argument against veganism. Other honorable mentions are "if everyone went vegan overnight it would cause problem X", where one's imagination is free to run wild about what might for instance be outlawed or interfered with, or "Where do you get nutrient X?" where that can be absolutely any bioactive molecule. Therefore, it becomes an unfalsifiable claim that one has not debunked all of the good arguments against veganism because falsifying such an argument would require an infinite set of counterarguments.
When it comes to using such reasoning to defend obviously silly positions that we disagree with, we would be hard-pressed to accept "Well you can't prove you've debunked all my arguments as to why 1+1=3, therefore there's probably some truth to it" as sound reasoning in any other context.
You can throw incoherent arguments one after another, but that doesn't mean that it somehow is as good as a cogent one. Pseudo-scientific positions for everything exist with a ton of bad arguments for them, including flat-earthers, HIV denialism, Holocaust denialism, and yes, even people that deny abusing animals for your entertainment is wrong. Just because they can generate a bunch of bad arguments for their untenable positions doesn't mean that it suddenly makes them right.