It's true that pigs are smarter than dogs. And they make wonderful pets. But we also farm pigs ourselves instead of hunting them to extinction. 3.5 million pigs per day, for 7+ billion humans. Not only that, sallow and bones are used for soaps, candles, biofuel, calcium supplementation and for some reason... making sugar white. That sounds as efficient as eating meat can be. Lots of animals just leave the rest of the carcass to rot. If it wasn't for condors/vultures to fill up the niche and clean up the mess, it would poison the water for everyone. As we see in area's where vultures are threatened.

Plenty of other animals are intelligient, and are killed by other intelligient animals. Take birds. They are pretty damn smart. Ever heard of the shrike bird who impales prey to mark its territory/woo females with food storage displays? The prey is alive upon impaling. Usually dead by the time a female dismembers the corpse. Isn't nature just romantic? Or what about humans being attacked by "dumber" predators. Humans may be intelligient, but it sure doesn't stop a hungry tiger/polar bear/hyena/etc. I don't think murder/hunting an "intelligient" is a good reason to label humans as worse than average. Though I do agree that pigs deserve better housing and space to express natural behaviours. Something mass farms don't allow.

A sea turtle (forgot the name) doesn't seem to eat the roots of the grass, but still pulls all of the plant out of the sand. Making it harder for the plant to grow back. Just like them, we screw ourselves over long-term.

Are we really the worst nature has to offer? I think we aren't per se. I think most animals given the oppertunity would destroy their enviroment, until they screw themselves over and a new balance in the ecosystem forms. Invasive species aren't a menace in the ecosystem they come from, only in spaces they aren't balanced in. We humans still need to adapt, and are lucky to be able to understand the impact we have long term.