[anyonecancode]

I think you have to assume that faster-than-light travel is both possible and economical. At that point, far-flung supply chains across the galaxy really aren't any more surprising than the far-flung supply chains across the globe of our current reality. When distance becomes less economically relevant, other factors (like labor availability and costs, regulations, ease of access, security, etc) become more important.

[hamdingers]

FTL isn't even necessary. Consider the majority of tanker ships travel at bicycle speeds[1]. If you're transporting sufficiently profitable nonperishable goods in extremely high quantities, and have enough automated ships, you could have a functional interstellar supply line at a fraction of light speed.

Of course, this isn't how it's usually presented in science fiction, but that's because a sci-fi story about a non-sentient fully automated mining machine wouldn't be very interesting. Gotta get humans out there.

1. https://en.wikipedia.org/wiki/Slow_steaming

[usrusr]

And they said five year plans struggled with predicting demand ;)

I'd rather go with "for any delta in mining convenience between solar systems, there exists a level of FTL magic where shipping would become economically feasible"

Perhaps space slow steaming might be an option if your goal was to make a Dyson sphere exist before the star inside burns out?