Not only because of the sensor sizes and quality (no way could the 50mp full frame sensor from the Canon 5ds/5dsr ever fit in a phone) while aperture can get fairly open (s7 has f/1.7 but because the lenses are so small it's not the same as what would be f/1.7 on a Canon or Nikon lens for a full frame 35mm sensor) and it's a fixed aperture. Not adjustable.
Another big reason smartphone cameras will never come close to actual DSLR's are the optics. Quality sensors are important but good optics are just as important. The tiny lens on a phone will never compete against much larger, higher quality glass, and more elements. Then back to aperture. A tiny phone lens can't have adjustable aperture, which is very important and 1/3 of the exposure triangle.
It's just physically not possible. Maybe over time some sensor could get there, but by then full frame DSLR sensors will have advanced even further as well. And it still would be missing half the puzzle that are the optics.