Sometimes. I carry one with me all the time too, and have a bigger one at home. Of course, I've got quite a few proper tools as well for more intense jobs. Not everything gets done with a knife.
But, multi-tools have their drawbacks. The biggest is that they're typically terrible for any of the normal stuff you'd do with a knife. Mostly that sort of knife is a last resort option. The steel, design, and ergonomics are usually garbage, and they are hard to maintain. They're slow to deploy, too small for a lot of things, not comfortable to carry. I could go on.
On the other hand, a well-designed knife with quality steel can do surprisingly well in a number of odd circumstances. The fact that my knife is incredibly versatile, extremely easy to pocket-carry, fast and simple to deploy, means that often it does the work of other dedicated tools simply because it's at hand. That's the big draw.
For example, if I need to cut that piece of paper in half, I could grab scissors. But, with a ruler and a knife, I can make that cut perfectly straight and do it faster. So, are scissors really better? I wasn't planning on doing a bunch of yardwork when I cut those branches Saturday, I was just walking by and noticed they were dead. So, I flipped out my knife and cut them down in less time than it would have taken to walk to the garage, get the hedgeclippers, trim the branches, and return the gear. Hell, it took less time than just remembering where the hedgeclippers were. That sort of thing happens all the time. I've used a knife effectively as a screwdriver, as a prybar, as hammer, as a ruler, you name it. It seldom works as well the other way around.
You might be surprised by much a small assortment of good EDC can improve your day-to-day well-being. The Fisher Space Pen changed my life!