This may be tangential to your point, but it's worth remembering that human intelligence has a very special property, which is that it is strongly domain-independent.

Not so fast. Human intelligence is relatively domain independent. But human minds are constantly exploiting known regularities of the environment (by making assumptions) to make better inferences. These reguarities make up a tiny sliver of the Platonic space of generating functions. By (correctly) assuming we're in that sliver, we vastly improve our capabilities compared to if we were AIXIs lacking that knowledge.

Human intelligence appears strongly domain-indepdent because it generalizes to all the domains that we see. It does not generalize to the full set of computable environments -- no intelligence can do that while still performing as well in each as we do in this environment.

Non-human animals are likewise "domain-independently intelligent" for the domains that they exist in. Most humans would die, for example, if dropped in the middle of the desert, ocean, or arctic.