The argument regarding intelligence is that the type of intelligence which humans show is rare on Earth as a evolutionary strategy. Other highly intelligent animals do not seem close to even the first steps of space exploration. Perhaps a better term than intelligence is 'culture'.
The fact that human abilities are very limited in some ways supports this. For most evolutionary branches it was a much better strategy to develop excellent eyesight, hearing, running or fighting than to trade off mediocre ones against a sort of general-purpose intelligence and communication skills.
>Other highly intelligent animals do not seem close to even the first steps of space exploration.
Ten thousands years ago humans didn't seem close to it either and yet they were same as us (and also same as their ancestors for dozens thousands years). 100,000 years is nothing on evolutionary scales and yet during this time our ancestors managed to outcompete other intelligent specie, Neanderthals and probably caused their demise. Considering what our species did to environment it's likely that as long as humans exist, another intelligent species can't evolve here.
Perhaps a better term than "close to...space exploration" would be "having a syntactic language." Humans of 10k years ago certainly had that, as probably did humans at least 4x that long ago. I think that's a pre-requisite for developing any kind of civilization that will develop technology.
And no, as far as anyone has been able to determine, neither birds, whales, dolphins nor apes have anything like a syntactic language, or even our vocabulary.
The comparison is not just with other animals today but across time. Dinosaurs dominated the planet for 100 million years but do not appear to ever have been as close to space exploration as the humans of 30,000 years ago.
Octopuses have been around for 500 million years. For most of this time humans were not holding back or inhibiting their propensity to study, receive signals from, send messages to, or travel to, other stars.
But it's not qualitatively different from other species' intelligence. It's just a sample from a distribution, and as such, only a matter of time and speciation.
The fact that human abilities are very limited in some ways supports this. For most evolutionary branches it was a much better strategy to develop excellent eyesight, hearing, running or fighting than to trade off mediocre ones against a sort of general-purpose intelligence and communication skills.