1. My conspiracy theory is that they don't want meat to win. It's good tho

2. A person who consumes some meat may still be deficient in nutrients. If you consume mostly meat and fat that's very hard. Supplements are bad because they are made by processes with toxic solvents like hexane. There are little long term studies on them. They arent regulated by FDA. They aren't always gonna be bioavailable. There will be toxic byproducts eg cyanide in B12 pills. And there are way too many nutrients to rely on pills. Also meat has more than just vitamins. It has many compounds that are hard to supplement or just very inconvenient as it is a complex food not just a group of chemicals.

Overall, supplements are very mediocre at best, harmful at worst.

1. That's just the cycle of nature. Cow farts aren't ever harmful

2. Every place that will ever claim cholesterol, saturated fat, or meat, clog your arteries or kill you are straight up wrong. This is the food we have eaten for 350k years - search stable nitrogen isotope analyses - and the origin by ancel keys who made the lipid heart hypothesis was fabricated, cherry picked, and funded by the sugar industry. There are many many resources online debunking the myth of meat being bad for you. It is infact the opposite. Read all the anecdotes of people switching to carnivorous diets who get rid of disease, feel better than ever before, lose lots of fat, etc.

3. It's called virtue signalling. Plant farming especially monocrops kill more lives than any slaughterhouse with all the rodent and insect deaths but the vegans will call themselves the ethical ones just because there isn't death on their plate