Why do all the bunkers look exactly the same, with the same layout inside?
TL;DRThe bunkers look alike because one or two were built as a proof of concept, with variations planned later using better tools, and the small level design team and other departments' dependencies also limit how fast more get made.
Well, I guess the simple answer is the one that we have mentioned quite a few times already. We build one or two to do a proof of concept and also see, is this something worth moving forward with? If we build something and players instantly hate it, that might also affect how we do stuff. So the easy answer is that we built one as a proof of concept, and in the future we're going to expand and add variations. Our tools are also developing. Our modular tool will help with, for example, the bunkers in the future when we add more of those.
I also think that the underground facilities go through the planetary surface. And that was actually, if I remember correctly, an early test on how to make caves go through the planetary surface. Because at some point in the past we were limited to very, very few cuts or holes made into the surface of a planet. We had like three on a planet. That's not much. So sometimes we add things to the game just as a proof of concept, not necessarily of a location but of some other tech that is happening in the background that might not be extremely obvious at first glance. We also have to keep in mind that the size of the PU level design team is fairly small. There are five level designers plus me. That's it.
We're also a small team, like Andreas said, but you don't work in a vacuum, like you said. So even if we could, in theory, white box stuff faster, we still need all the other departments as well. You need sound, you need art, you need VFX, everything like that. All the teams need to get their stuff in.
There are a lot of interdependencies.