Enoki
SOC-14 1K
The huts in the Arctic used by Scott and Shackelton would clearly qualify as abandoned but where left in excellent shape for possible use later. When the US left the Solomons and other islands in the Pacific, we pulled the people out and basically left every else except usable weapons. It was too costly in terms of shipping to get everything out. When the Japanese surrendered on Bougainville and at Rabaul, the people left, every else stayed. There are still large number of caves stuffed with Japanese equipment in the Northern Solomon Islands and at Rabaul on New Britain.
It would depend entirely on how the outpost was abandoned. Were the personnel suddenly pulled out for some reason, or left suddenly when ordered? Did the civilization breakdown and the personnel slowly die off? Did a supply ship fail to get through and the personnel starve to death or suffer loss of life support? Did the outpost personnel suddenly die of a virulent disease contracted from the planet, which is not deadly to humans? Was all but one or two of the persons operating the outpost killed in a sudden disaster, and the remaining ones suicide? There are a lot of possible reasons for an outpost to be in quite good condition.
Yes, it would depend on the length of abandonment and if anyone else had been there before... Another possible twist... They're back! Certainly the planetary conditions would matter too.
But, in terms of a scenario having junk, trash, and stuff everywhere gives the players the potential for a "treasure" hunt through it.
If it's all nice and neat there is less mystery other than "How does this stuff work?"