Greta wrote: If a different species was the one to become abstractly intelligent and dominant as humans have done, I expect they would make the same kinds of mistakes, including delusions of grandeur. Why wouldn't they? There's been no precedent on Earth for human abstract self awareness and there continues to be much trial and error in the way we do things, and enormous uncertainty about the future.
Why do you assume that there are not other species that are "intelligent?"
The egoistic yardstick we humans almost always apply can only measure that which we feel is worthy. If you observe how most species are doing out there, it seems as if they might be considerably more "intelligent" than are we who seem to believe that we can out think a Universe that spawned us.
Who among us does not [deep down] believe that we are but a temporary surface nuisance on this planet?
You seem eager to make the point that humans big note themselves; ideally you will save your ammunition for those who don't agree with you. That is why the qualifier "abstractly
intelligent" was used rather than just "intelligent".
However, let's not be postmodern about this, just because some very noisy people are either amoral or rather stupid, or both. We humans truly are more intelligent than other animals in the same way as mammals are smarter than reptiles, which are smarter than (non-mullusc) invertebrates, which are smarter than microbes. The evidence is not only in brain structures, with our extra cortical folds and brain structures devoted to higher mental functions, but also in technological achievement.
What confuses people is "domestication". An example: while it's often assumed that wolves are smarter than dogs, this is wrong. Wolves are smarter when it comes to dealing with seeking, hunting and other skills required for the wild, things they have had genetically ingrained and practised. Dogs are smarter than wolves in terms of communication with humans and capacity to adapt to human weirdness (which is how it must surely seem to them) - again, ingrained and practiced attributes. I suspect that we take for granted just how skilled we all are in "operating the machinery" of our societies, and what a complex and daunting thing this would be to those unfamiliar with the concepts.
"Domestication" in humans has similar effects, and it's happening quickly. Thus, each individual is less "complete" than individuals in the past (and many wild animals). This is because we, like our dogs, live in a eusocial society, an arrangement unique amongst chordates, aside from naked mole rats. In eusocial societies - most famously ants and bees - members have a much narrower range of abilities than free living individuals. Instead the have the ability to coordinate with human societies, and it's the total society that grows in intelligence and capacity rather than individualists. The except is specialists so, while much of the population remains functionally mediocre, eusocial societies produce "experts", specialised individuals with ever greater capacities, eg. science, sport.
In a sense we humans are akin to mitochondria, which lost their ability to live independently but, in becoming a crucial part of eukaryotic cells, they came to effectively dominate the globe.