That already happened to some extent. I remember reading a huge article about devices that make other devices obsolete.
With cameras the point remains that you can't really put huge optics into a cell phone and while it might seem strange cell phone cameras haven't evolved much for the last 5-7 years. Do you remember first Sony Ericsson cybershot phones? They had 2mpx, then 3mpx sensors that could take pictures that were at least as good as average modern smartphones. It's just that now it's a standard. Indeed cell phones might make cheap point and shoot cameras obsolete but then again some people would rather buy a sub-100$ camera than a 400$ smartphone for similar effect (right now most sub-100$ cameras would take better pictures anyway, plus they provide pros of better optics, zoom etc.). But for a lot of people who already own these phones buying a really cheap camera would be pointless, so they definitely endanger their sales.
With cameras the point remains that you can't really put huge optics into a cell phone and while it might seem strange cell phone cameras haven't evolved much for the last 5-7 years. Do you remember first Sony Ericsson cybershot phones? They had 2mpx, then 3mpx sensors that could take pictures that were at least as good as average modern smartphones. It's just that now it's a standard. Indeed cell phones might make cheap point and shoot cameras obsolete but then again some people would rather buy a sub-100$ camera than a 400$ smartphone for similar effect (right now most sub-100$ cameras would take better pictures anyway, plus they provide pros of better optics, zoom etc.). But for a lot of people who already own these phones buying a really cheap camera would be pointless, so they definitely endanger their sales.