A lot of cameras are for sale with such additional compute, but the only people with them are developers. Corporations that want/need security tend to have large legacy camera networks that one is lucky if they support HD resolution above 720p. I worked for a leading enterprise FR video security company, and the majority of their clients are firms with anywhere from a few hundred to several tens of thousands of original generation IP cameras, which they very slowly replace with something as close to what they already have. They want to continue to use their older cameras too, often because their network and number of cameras fit, higher resolution and greater bandwidth cameras simply can't fit into their live and operating design.