Hey, thanks for such an awesome and thoughtful reply.
There are many things that can makes us sick, removing them aids recovery.
I would not say, that everyone "should" eat meat, thats not my business, I love to see people try different stuff. So long as they are honest, so as not to pass on terrible advice.

Most people do carnivore because nothing else worked.
Now that is changing and people are doing it because it works so well even without any disease or pain state.
Fat adaption to athletic standard - yes that can take many months, I feel that exercise helps the adapting, but it still takes time.
Vegan - a long time ago, several times a few months each only. Vegetarian I tried using duck eggs and home grown veggies - about 6 months.

Veganism encourages autophagy similar to the way that fasting works, like fasting it can give great results - until you run out of something essential.
If a person formulates it really carefully and is not already too damaged, they may last a long time, especially if their standards are very low.

Most of us are quite damaged from a thousand cuts - agriculture and industry have not been kind to our biology even if they have made life more comfortable.

Take Care!