The Powershot isn't a DSLR, it's a point & shoot. DSLRs have an optical viewfinder and a reflex mirror that allows both the viewfinder and the sensor to see the same image (not at the same time though).*
I do love using my phone (Samsung Galaxy S3) as a digital camera as well, especially since it does take good pictures, and I have it with me a lot more frequently than I have my DSLR. But DSLRs are way more flexible. I hate how cell phones lack a manual focus, aperture and shutter priorities, have small sensors and (usually) no optical zoom. I find phones to be way more convenient than actual cameras, but in a lot of applications (especially low-light situations), A DLSR would normally perform a lot better.
*A lot of people will also include interchangeable lenses in the definition of a DSLR, but in reality, the name DSLR only implies three things: digital sensor, single lens, and a reflex mechanism. There have been a few DSLRs, such as the Olympus E-10, that did not have interchangeable lenses.