https://www.webmd.com/diet/difference-between-animal-protein-plant-protein

https://www.health.harvard.edu/blog/plant-based-diets-are-best-or-are-they-2019103118122

Basically it's harder to achieve all essential amino acids in a plant based diet. Animal protein is also linked to lower stroke risk and diabetes, but can lead to higher heart disease. Overall it's not absurd to say animal protein is better than plant protein.

On the last comment: https://rainbowrunfarm.com/how-many-people-can-a-cow-feed/

This source claims one cow can feed one person for 8 years, but that feels a bit absurd so I did my own math. 80% lean beef contains 1152 calories per pound. Meaning at 2000 calories a day one person eats 1.74 pounds per day.

https://beef.unl.edu/beefwatch/2020/how-many-pounds-meat-can-we-expect-beef-animal

This source claims about 880ibs of useful meat is available on the average cow, meaning one person can survive for 505 days on one cow, or 1.38 years.

The third source claims one acre per cow raised is the land needed for grazing. Checking other sources this seems to be the general consensus on cattle to acre ratio.

https://permaculturism.com/how-much-land-does-it-take-to-feed-one-person/

This source claims you need 1.69 acres of land to raise all the required plants in order to feed yourself for one year. Therefore raising the cow and eating it would be a more viable space.