I've been playing with my outposts for the last few days and I can now say with confidence that they are completely useless. The problem comes down to how storage and cargo links work.
FO4 had a simple "network" system. Add a node to the network, and all nodes had access to all materials at all other nodes. That encouraged you to use each node (settlement) to specialize in some kind of resource, which became building blocks for your crafting node.
In Starfield, you only have access to the material in your backpack, ship, and transfer storage. Everything else is stored in unlabeled boxes that you keep adding as you run out of storage. If you need a mat that isn't in your backpack, ship, or transfer storage, you have to manually search for it amongst all of your unlabeled boxes. You can attach an assembly machine to a box, but how do you get the right materials into the box? Manually? Everything time? Great fun.
Rather than networking your resource outposts, you daisy chain them. Your first outpost sends everything to your second. Your second takes all of that, adds its own, and sends it to the third. By the time it gets to your crafting outpost, the transfer pipes are hopelessly clogged and you get nothing but your final outpost's resources showing up. What can you make with Beryleum and He3? This doesn't really matter because what would you have done with the unsorted mess from all of your other outposts? You can't feed it automatically into your construction machines, because you will, inevitably, not get the right mix of goods.
So I now have 5 outposts mining elements I can't use and shipping (some of) them to an outpost that can't do anything with them. This is hopelessly borked and I will now move on from outpost building for approximately 18 months, after which BGS or modders should have a functional replacement system available. Until then, it is literally pointless.
BTW, I am not a Starfield hater. I just logged my 123rd hour and I'm mostly having a good time. But this seems like a lot of work went into making something that just doesn't do anything useful.