> If you have data that supports this assertion, show it.

Aside personal anecdotic evidences of cats thriving after +10 years of vegetal feed, here's some:

> Considering these results overall, cats fed vegan diets tended to be healthier than cats fed meat-based diets. This trend was clear and consistent. These results largely concur with previous, similar studies

> In most cases differences between dietary groups were not statistically significant

[2023, 127 cats in the vegetal group] https://journals.plos.org/plosone/article?id=10.1371%2Fjourn...

I admit that's not much, but If you think about it there's no reason a carnivore may not live healthy if provided the right nutrients, whatever the sources. Those nutrients are already well studied -especially for one of the two most common pet- and generously added in kibble because the base is often poorly balanced.