I wanted to follow up on @John O's comment, there are a couple of obvious uses
The extra space can be used to store things you didn't have enough room for without wormholes.
A base inside one of these wormholes will have fewer entry points than one out in open space. A bank inside this wormhole has fewer directions to be attacked from. A prison would be virtually inescapable.
Because of the previous point, observing what's happening inside this wormhole, from the outside, is easier to prevent. You just cover up the entry points with heavy shielding and no one can see the experimental weaponry you're building on the inside.
Because of the limited number of entry points, you have an easier time controlling what is inside the passage. This can mean a reduced amount of debris endangering fast moving vessels, but it can also ensure the safety of very important cargo passing through. Sure, the traveled distance is longer, but that can be worth it if you can ensure the safe travel of, for example, the president between the capitol and their home planet.