We do have foods formulated for cats which involve 0 animal products. Obligate carnivore only describes an animals diet in nature. With our current technology, we are very capable of creating food with all of the required nutrients for cats in a form they can absorb effectively without any animal involvement. We even have studies showing that it is better for them, ie https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0284132