The main thought behind a multi-tool is, you carry it on your person and it contains, in a compact package, common tools that are useful in many different situations, be it survival or otherwise. It's the equivalent to carrying a small tool box in your pocket. Sure, it’s most useful in an urban/suburban environment, but pliers, knife blade(s), saw, file, scissors, and flat pieces of steel (screwdrivers) are such generic tools that they can be useful everywhere.

I normally carry a Leatherman charge Ti (which is expensive at ~$100), but I also have a few Leatherman Blasts that I carry occasionally (which have a similar tool selection). The Blasts cost me $30 at Walmart and work just as well. For $30 I couldn't fathom not carrying it, it has come in so handy so many times it has more than paid for itself. Fixing a stove on a hiking trip, fixing someone else’s flashlight, fixing my glasses, lifting hot objects, scraping, prying, making holes, cutting barbed wire I got tangled up in, ect. Uses are only limited by the imagination.

I also carry a full toolbox in my vehicle, but I know from experience that if it isn't on your person it wont be there when you need it most.