Panthers, mountain lions, pumas, etc. are from the same family of cats. They are the most widespread native mammals in North America, next to people. In other words, they are numerous. They are intelligent animals and they avoid humans except when they are convenient prey, like the ones in the urban/rural interface areas of California. I run on rural roads in my East Texas community, often at night. If panthers were that common and fearless here, I would have to pack a large caliber gun for protection.
Panthers have not lost their place in the food chain. They just adapted better than other mammalian predators.