Complaining can be a solitary affair, but often it likes company. It's a bit of an extrovert. To have company, it must have an accomplice.
A few years ago, I came home late after an eventful day in a period of an unusually heavy schedule of obligations.
I let out a stream of complaint, not about a person, about external matters, but in the presence of a person.
The person said, not looking at me, but gesturing in the general direction of my words:
"That has to stop. If you permit it, it will take over."
Another time, the same person, when I complained, said. "Right, so, what are you going to do about it."
This was genuinely helpful.
Listening to complaining reinforces the narrative: it does not provide lasting relief.
When I'm listening to others' complaints, I'm not supporting them: I'm aiding in their destruction.
Redirection of my attention to the solution was what was needed, not sympathy.