In the video game Rimworld, the "rim worlds" are worlds that are far away from other inhabited worlds.
Often, they are characterised as worlds that are very isolated (due to there being no FTL travel in this universe), and often dangerous and impoverished places that are hard to survive in.
Pirate raids, slavery and just overall misery are rampant, and the occasional mechanoid attacks don't make things much better either.
They are sparsely populated, often in the form of tiny settlements that are spread out over the planet, many of which often raid the others for resources.
However, in Rimworld (the game), there is some advanced technology available, such as air conditioning, hydroponic farms, neuro-simulators, and the occasional merchant even carries AI cores or advanced "glitterworld" medicine (at steep prices), and trade with passing trade ships (in orbit) as well as some space travel does happen (the latter being the main objective of the game, mostly just to get away from the place).
What prevents the few settlements that exist from organizing themselves, industrializing and applying their knowledge of advanced technology to make the place a bit less of a hellhole? What could cause such a planet from remaining in this state for a long time?