This article describes many reasons why if everyone went vegan the world would be a better place: https://www.bbcgoodfood.com/health/special-diets/what-would-world-look-if-everyone-went-vegan
Some reasons include:
People will be healthier
The environment will be better
There will be more food for everyone
Animals will be happier
I would add:
People would no longer work in slaughterhouses and suffer the negative physical and emotional consequences.
Here is some info about that topic:
https://pmc.ncbi.nlm.nih.gov/articles/PMC4841092/
https://sentientmedia.org/slaughterhouse-work-exploited-labor/
https://pubmed.ncbi.nlm.nih.gov/28506017/
https://bitesizevegan.org/ptsd-in-slaughterhouse-workers/
