I use knives to duburr things like the inside of a cut pipe or open up a hole etc. I like a swedge on a knife that's used like that (where the spine is riding against the inside of the cut) because it rides over little bumps in the cut more smoothly which reduces the tendency of the edge to gouge. It gives a smoother cut.
A large swedge can take some weight off the end of a tip heavy knife without some of the disadvantages of a clip.
When used as a design element it is a way to drop the shoulders to create a diamond cross section of a reinforced point, where you want the widest part of the blade (the shoulders) directly behind and in line with the point.
A swedge can be functional, not just for looks. It's a tool in the arsenal when you're trying to shape a blade for a particular use.