This means that human technologies don't matter.
You know, you mentioned eldritch horrors. I don't understand why they would care about studying humans. But to make it more general. As I said, why must it be humans? Why can't aliens study the culture of the defeated and wiped-out society of anthropomorphic animals who used to rule the world(earth)? What will change in the story?
Some aliens from Mars used: For the first one insane power, clever killing weaponry that bypassed human weapons or bring too powerful to bother with human, I don't know it could a number of things. And wiped out anthropomorphic animals of the earth who had their culture, society, technologies, etc. And NOW: it's still earth the rules of earth their history and tech will still influence scholars to want to understand, learn and improve on what they did, it won't directly affect the story but it will be a nice extra bit of info for the readers. What changed here? What will change if we swap anthropomorphic animals with humans, or elves, or demons, or symbiotic creatures, or whatever else?
A nonhuman protagonist is similar. I completely agree here. And if we exclude humans from the story and have a nonhuman protagonist, we basically get the premise the OP wants to do.