Professional photographers are still going to prefer professional cameras . Weight and size will be an important factor, but the photographer community will still appreciate the extra versatility offered by a DSLR camera, the feeling of working with a professional instrument, and the extra quality of the image.
Image efficiency keeps improving. The performance of smartphone cameras is improving rapidly, but so is the output of DSLR and mirrorless cameras. So its hard to say that smartphone camera will take a leap anytime soon.
A DSLR camera always remains one level up. Many photographers will start their journey with a mobile camera, but they will invest in a DSLR or mirrorless camera once they get more into photography and want to get better. A smartphone remains a more professional tool than a camera.
There are many options to choose between. You can choose between several models when selecting a DSLR or mirrorless and find the one that best satisfies your requirements. A camera is a camera, nothing more but smartphone comes with many features and you need to find a smartphone with best overall features which is really difficult to decide.
Lenses make a difference. Any professional photographer knows the importance of high-quality lens. You’re much more flexible when using a DSLR camera and can use different lenses for different purposes, but that is not possible with smartphone cameras.