Detriment to humanity

Most countries subsidize agriculture to protect it from competition. In countries like the US the subsidies reach billions of dollars a year. The burden of subsidization falls on tax payers, and this money could be allocated in a way that prioritizes humans flourishing: education, medical care, humanitarian support of starving countries. 

Animal agriculture wastes resources like viable human calories (43% of crop land is allocated to animal feed growing both human crops and feed-specific crops (soy, corn, wheat, alfalfa and other crops). Animal feed is also very heavily supplemented with both natural and synthetic vitamins and minerals, wasting resources through the increase in trophic levels. 

This is something that most humans care about. Our gluttony for animal use exploded the biomass of farmed animals while reducing the biomass of wild animals. From destroying their habitats to killing them because they intervene with food production. Examples: wolves who try to predate on livestock, badgers who are blamed for the spread of Bovine Tuberculosis in the UK, and even animal deaths for crop production that are intensified by the need to grow animal feed.

In food production, generally speaking animal rearing is the highest GHG producer, highest water spender, highest land user and deforester, and energy spender. If globally we eliminated animal foods, we would reduce the use of  land and water use by 75%. 

Food production is responsible for 25% of our GHG emissions, and reduction of 75% of those emissions would reduce our total emissions by 19%. 1 kg of beef produces 60 times more GHG than 1 kg of peas. 

Leather production has some environmental benefits once it's a product, but its production is more environmentally degrading and destroys entire regions. Replacing leather production even with the plastic leather would reduce GHG emissions, water use, and regional destruction, but best practice would be replacing leather with durable vegan leather alternatives. 

The leading causes of death are related to overconsumption of animal products. Processed meat type 1 carcinogen, saturated fat & cholesterol are linked to heart disease, and it's easier to overconsume on an omnivorous diet, which leads to obesity, increasing risk of diabetes and other onset issues.

Animal testing is argued to hinder the invention of treatment. We can cure cancer &heart disease in mice & we progressed some in the treatment of humans, but since animals are easy to exploit, we keep doing that instead of looking for better alternatives. 

These are worst diseases that have been plaguing humanity, especially in the past 100 years - the flu, AIDS, COVID, TB, and about to get another avian flu. There are other ways, but I just woke up, might add to this list later. 

When we don't like a group of people, we dehumanise them, which includes "downgrading" them to animal status, and treating them accordingly. Animal practices were used to holocaust jews, romanis, lgbtq in 1945, and today we also gas pigs to death.