Out-of-order and damaged spacecraft spare parts, station debris, lost cargo and other small remnants of human activity in galaxies are the main source of the constantly growing amount of space debris.
Unfortunately, the well-established waste recycling system in the cluster appeared only recently. Previously, it was considered a norm to throw a couple of tons of leftover polyonium armor damaged in battles into outer space, whereas now in such a situation it would be more rational and profitable to recycle it, thereby saving some resources on repairing your ship.
In some galaxies, particularly large piles of space debris have begun to gather into whole garbage clouds, which of course can be an unexpected unpleasant surprise for cluster researchers, since such clusters can slow down movement, or even damage the hull of the ship.
It should be noted that accumulations of space debris can become a great source of rare resources, for example, polyonium left over from the skin of spacecraft, or hydrazine that has not had time to completely drain out of discarded fuel tanks.