IMHO, camera smartphone will definitely affect the sales of low-end P&S, but might actually increase the sales of high-end P&S, mirrorless camera & DLSR.
Those who interested in photography will get a high-end P&S, mirrorless or DSLR at some point of time. Those who not interested in photography will not buy a decent camera with or without the existence camera smartphone. They might brought a low end P&S to satisfied the need of taking photo in certain occasion.
With the introduction of camera smartphone, more people will be taking photo and those who initially not interested in photography, might get into the hobby. If they do, they'll eventually get a high-end P&S, mirrorless camera or DSLR due to better image quality... especially the interchangeable lens camera.
By the way, the "100% view" button on the image viewer is the ultimate larger sensor camera promoter... once you press it, it's hard to resist not to get a better camera... ha ha ha
Have a nice day.