Sony is clearly listening. Their range of mirrorless cameras (NEX before, and A6??? now) seem to cater exactly this segment.
I shot Sony since the NEX series came out, starting with the 5000R. Paired with a fixed Zeiss 24mm this camera took absolutely astounding images. Pair a Sony with a smartphone and you get easy upload to social media. What's missing, exactly?
Incidentally I sold all my Sony gear last year. The UI and handling of these cameras is just as ugly as any smartphone can be. It takes seconds to start. The animated/touch UI is just fancy, but slows any operation down. Most modern cameras have humongous menus which are hard to navigate and make little sense as dozen of features get added, but Sony is really on the worst end when it comes to placement and behavior of all the functionality they pack into their cameras, which is sad.
Their "app" store is the most useless thing I've ever seen, including stuff which should be bundled in the camera but when used precludes the functionality of the camera itself.
I'm lucky I always had a great group of friends from which we exchanged cameras and I was able to use most of the others you mention too. If you pick any Nikon, Canon or Fuji camera and start taking pictures you immediately realize why menus are placed in a certain way, the UI is intentionally minimal, and why the body is shaped the way it is. It's a night and day experience if you know what you're doing. No operation takes more than half a second to perform. It's form-follows-function. These cameras cater to pros _first_. You don't need to upload to social media and/or you basically never want to have smartphone-like post-processing in camera because the normal workflow is to either take the built-in jpeg because it's already good enough, or process the raw yourself. Transferring the image via wifi/ble/nfc is decent enough in most 2017+ mirrorless cameras.
Granted, Sony made _huge_ steps forward since the NEX line, but you can definitely see how the camera is influenced by the smartphone market. Sony even released the QX1, which essentially is a camera _for_ the smartphone.
Somehow I have the impression that smartphones themselves will eat away all the middle market as the small optics keep improving. If you want images for instagram you'll probably never care about the improvement in image due to a larger sensor anyway. But a pro will definitely seek superior handling and behavior in a camera, and that is almost tangential to how a smartphone operates.