The author of the article you mentioned (Alex Howe) is a good example for what I insinuated: He takes issue with Korsgaard's argument (and, it seems, Kantian ethics more generally), but in his PhD thesis argues for granting "basic citizenship rights" to domestic animals (including farm animals), which is arguably a far more radical position than veganism, which merely posits that it is immoral to exploit (or be cruel towards) animals (e.g. as a food resource). Either way, if you have an issue with Kantian ethics and how they are applied to animal rights, I suggest you take it up with a Kantian (which I am not). And, even if I am repeating myself, none of this has any direct relevance to my earlier point, which is that many moral philosophers from many different schools of thought (including, but by no means limited to, Kantian ethics) have arrived at conclusions which are at least similar to the basic vegan stance, i.e. that unnecessarily causing harm to (sentient) animals, e.g. by exploiting them as food, is immoral.

i read that something like 1/3 of all human caused extinctions are because we keep bringing cats with us

Do you have a source for that? Intuitively 1/3 of all species extinctions (keep in mind this in general includes plants and other kingdoms of life, not just animals) sounds far too high imo. Maybe you have read that number in a slightly different context, like bird deaths in urban areas, or perhaps in a more specific context similar to the one in your link? Don't get me wrong, like your link shows, (house) cats can easily have a devastating effect on the local wildlife, in particular birds and small mammals or reptiles (wikipedia has an article on the topic, although I didn't find anything like your numbers in it). But as far as I know the major ways in which humans have caused extinctions are historically overhunting (mostly affecting large birds and mammals), habitat loss in particular since the advent of agriculture, and more recently of course the effects of the climate crisis since the industrial revolution.

they are not sentient

Science disagrees with you here. Most of the animals being used for meat are in fact not just sentient, but also conscious:

Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors. Consequently, the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates.

-- From the Cambridge Declaration on Consciousness

Humans have put multiple species on the verge of extinction.

That is a slight understatement:

The Holocene extinction is mainly caused by human activities. [...] the current rate of extinction is 10 to 100 times higher than in any of the previous mass extinctions in the history of Earth.

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