It really depends on what you want to do or how far you want to go.

The smartphone has the portable hability and with esteem/ecency the main advantage is another camera and storage available. It lacks in zoom quality but can perform small zooms without a problem probably.
Historically the software doesn't measure light as good as DSLR's but they have been improving and sometimes can solve some low or mixed light situations faster than DSLR.

The DSLR depend on the objectives / lens that you have and will have limited zoom with a 18-55 / 18-70mm for example, but can expand or come with a 18-180mm, then there are the tele zooms 70-300mm, etc, and you can get a fix range like 35mm f1.8 or 50mm f1.8 and they can do low light situations without pushing the ISO sensitivity as much.
In general i prefer it because the manual mode allows full configuration of the photo, but you can also use semi-auto modes and just tweak one setting (shutter, aperture).
The glass of the lens also provide another level of quality.

;)