I dislike a lot of the shock advertising they do, but most of what you point out is anecdotal and mostly spread as a laster campaign, because they actually do have an impact on animal welfare and that’s not in the best interest of the ppl behind these laster campaigns.
About the shelters, what should happen with all the excess pets that are bought and then dumped? At least peta tries to take down bad kennels and does something about the stray population. It’s all nice having a no-kill shelter, but these either don’t take all pets or get to big that it’s just unhygienic and sad. If the shelter refuse any ill or old pet they can’t place, these pets either end up on the street or in a shelter that takes any pet and does euthanize.
Peta also gets called for stray pets in terrible condition or that are aggressive that probably always have to be put down.
Their kill rate will probably be quite high, but I have no idea who made up the 80% and what would be included in that number.