I mean, most of what you do in life is a habit. Diogenes of Sinope lived in a barrel. Your ancestors lived without electricity, some without running water.

If you want to drastically cut down on wasteful spending today, I remember a great blog: https://www.mrmoneymustache.com/blog/

In any case, humans do seem to need the vitamins and minerals in meat, but if the animal is older then this can cause them to age faster as well over time.