The situation with pork vs. wild boar is very different from the elephant, and more analogous to beef vs. the Cape Buffalo. We don't need to hunt wild boar for

The situation with pork vs. wild boar is very different from the elephant, and more analogous to beef vs. the Cape Buffalo. We don't need to hunt wild boar for meat thanks to factory farming of pork. Tracking a boar in the woods just for its meat makes no economic sense. We hunt the boar mainly for the experience of killing a dangerous and intelligent animal. But selling experience is hard to scale, esp. because only a very small subset of humanity has been allowed to engage in that sort of hunt (formerly by legally enforced social class distinctions and land ownership, more recently by cultural norms). As a result, the hunting of boar is kept to a sustainable level. As for the elephant, we don't need the meat either. And if hunting were only for the trophy hunter's experience, it would be sustainable. But the problem is the ivory: plastic is not a good enough substitute, so prices for the real thing are astronomical, and industrial-scale poaching of wild elephants makes economic sense for the unscrupulous. If we farm-raise enough elephants to drop the price of ivory to the point that poachers could gain more from other illegal pursuits - illegal mining, stealing non-ferrous metals from construction sites, tapping into oil pipelines etc. - we would save the wild elephant.