thing I didn't add to the literary criticism terms list but I also see and think about a lot, I just don't have a great name for yet: the thing when sci-fi archaeologists go to a sci-fi planet and there are the ruins of a civilization where everyone has been dead for 10,000 or 50,000 or 1 million years or whatever. No survivors, no descendant communities, no one else living here anymore, just empty ruins. And because everyone is completely and thoroughly dead and gone, only the (usually human) discoverers are left to put together the pieces of what this once-great civilization was like. It's not really the same thing as Big Dumb Object sci-fi, it's very much framed archaeologically: planetbound ruins, artifacts, remnants, ancient scripts. And it's a clean break from the past to the present, no continuity. The protagonists now know this society better than anyone else, because there's no one from this society left to know it. And due to this, they kind of get the authority to make declarations about it, about how to interpret it or what's worth preserving from it.
On the one hand it makes sense because space is the place where you can get the timescales to meaningfully do this. Species that arose and went extinct long before humanity even existed - yeah you can imagine those in space. The speculative appeal is strong. On the other hand, this is not how archaeology works anywhere on Earth. There are always people there no matter where you're digging, and USUALLY they will have some connection to the stuff being dug up. The actual on-the-ground politics of that relationship are very different where you go in the world, but anywhere there used to be people there still are people. And that is almost never true in sci-fi archaeology. And obviously sci-fi allows us to speculate, but it's the pattern you see again and again. No one's interested in speculating an alien archaeological site where those aliens' descendants or anyone related to them are still around in any meaningful capacity. In sci-fi, descendant communities just do not exist. Everybody Died. This place now belongs to no one anymore, except the archaeologists.