The Star Pit by Samuel R. Delany
An audio drama version is available free online:
The story takes place in a time far enough in the future that not only is faster than light travel around the galaxy possible, but intergalactic travel is technologically feasible as well. However, we are told that as a starship gets beyond a certain distance outside a galaxy, the scarcity of matter causes a change to space-time that tends to drive humans mad and cause them to die. Only certain humans with particular psychiatric conditions can survive intergalactic voyages. Society encourages a certain number of these people in order to obtain rare items from other galaxies.
That background provides a context running through the story and some characters are that kind of person. However, the story does not take us on any such journey and does not center on those people. The "Star Pit" seems to be the maintenance area of a spaceport. Our main characters work in repair shops for starships. In spite of having starships able to travel to other galaxies, there doesn't seem to be much advanced tech in the lives of people working at the spaceport. They seem to live in a dingy place many of today's blue-collar workers could recognize (starships excluded, of course).
We are first introduced to the main character through an episode in his past. He had been part of a group marriage for raising children (which seems to be the common way of doing it at this time). However, his drinking problem leads to issues there. Then we see him working at the spaceport, apparently years later. He tends to try to help out youths looking for a job in the local repair shops. His interactions with one youth working at a friend's repair shop seems to be the core of the plot, such as it is. But this is more of a plot one might find in straight drama - where one observes people muddling their way through life. It's not one of the kinds of SF in which sense of wonder, tech, strange worlds, adventure, new ideas about the future, aliens, utopias, dystopias or such things are central. Nor is there any conclusive riding off into the sunset.
For my tastes, I’m left with the feeling things happened, but the story “didn’t go anywhere”. Readers more inclined to drama in general or Delany in particular may find it more rewarding.