Futurology

Ya, personally I lean more towards a combination of rare complex life and rare intelligence. For all its value in the modern world, a big slow brain that wastes a lot of reaction time and calories on abstract thought is not particularly useful to things like avoiding predators.

Given how long it took for earth to go from having millions of different complex multicellular creatures to having a single one reach complex abstract thought, I am willing to believe that having the luck to beat the evolutionary pressure to make a simpler faster brain is very rare, and we are just lucky that it happened so soon on earth.

Combine with the conditions for complex life to grow and continue existing to roll thouse dice for long periods of time being in and of themselves extremely rare, and I think it’s resonable for us to just be an early outlier.

The problem however with expecting aliens to exist, at least within a few hundred million light years, is that the foundational bedrock physics of our universe mean nearly any advanced technological civilization should be extremely and painfully obvious.

We could miss another world like earth is currently, but on an astronomical timescale humans going from discovering writing to the point where we have solved science and are engaging in galactic cluster scale resource exploration, extraction, and conservation. We live in a reality where on astronomical timescales everything not actively saved will be lost and destroyed, so we would expect any intelligent civilization to try and preserve at least some of it, and anyone doing so should be obvious to us since at latest the first infrared telescopes we’re put up.

It’s not that they didn’t want to bother contacting us, but rather that they would have had to put significant effort to put us in an artificial zoo to not be visible. Even then, we don’t hide the airplanes flying at thirty thousand feet from the elephants on some reserve, and I can’t imagine many reasons to put so much effort into trying.

Far less contrived is for the reason we don’t see any alien activity among the stars to be simply that there isn’t any close enough to be visible yet.

Personally I think it’s probably just that our environment is rare.

That could be. Nobody has any idea under what conditions tectonics start; it could be super narrow. It may or may not be required, but if it is Earth might be exactly the right size and composition to allow long-term good conditions. Speaking of, there's also theories where planets migrate over time. If we had ended up too close to the sun we'd be another Venus.

This is all mitigated by just how many stars there are within nearby galaxies, though, so it has to be really unlikely for aliens to evolve and then roll out big things across interstellar space.

And then just let them deal with their challenges in order to mature.

That's implicitly assuming whig history, just saying.

And afaik evolution can settle like it did with the dinosaurs, where nothing much new happens.

Not quite, it didn't really settle. We compress like 200 million years of dinosaur evolution together in our imaginations, but that's not actually what happened. It's hard to say if technological bird-like creature would have happened without Chicxulub, but given what our ancestors looked like 70 million years ago and how smart existing birds are it doesn't seem far-fetched. Having worked with birds and heard about crocodilian behavior it would be a really weird civilisation, though. Maybe not even a viable one.

And further, why establish contact with humans?

Well, if they exist and expand, it wouldn't be a matter of calling us or not, they'd have to actively hide or we'd see them.