Without highly portable fabrication facilities, you’re stuck bringing what you can carry. It’s not enough to get an entire population started, so aside from a seed of technology, mostly you have to work from what you can wring from the planet.

Until the colony world produces enough to be worth the advance world’s while, it can’t afford to buy the advanced technology and people are too busy staying alive for quite a while to build the advanced fabrication plants which have a long build-to-payoff cycle.

This idea doesn’t seem entirely consistent the Firefly universe Tthis idea works better with sublight cryo-or-generation ships and colony worlds spread across light-years — thus moving goods is really expensive and generally not worth it except for high-value-to-mass goods.

Firefly takes place in a single solar system which can be transitted in (it seems) a few weeks at most with the constant-boost gravity-controlled ships they have. It’s harder to justify the colony worlds having more primitive tech in that case — perhaps less of the tech, but why is it also more primitive?

Nevertheless, I really enjoyed the series and the movie.