Maybe the most plausible third options is that we are theoretically not alone in the universe and complex life is abundant, but the universe is so big that there are no way we can contact with any of the intelligent life forms. We're just underestimating the size of the universe.

It's like living on a Pacific island 5000 years ago. There are definitely other people in the world but there is no way you can contact them.

Distance is not such a great obstacle if you have time. Aliens could conceivably live much longer than humans, making many thousand year journeys feasible. Or they could send effectively immortal machines instead, maybe via something like von Neumann probes. Generation ships are also possible.

These distances only seem long to us because we're thinking mostly in getting to other stars in a single human lifetime, which is a pretty short lifetime even compared to some other organisms on Earth (like trees, not to mention organisms that can go in to stasis indefinitely, like the mushroom spores of Terrence McKenna alien contact hypothesis fame). Once you remove the limit of a single human lifetime, your reach expands greatly.

The many billions of years that the universe has existed should give an advanced civilization plenty of time to visit the entire galaxy, either in person or by proxy, without even having to invoke the possibility of FTL drives or wormholes.

If that's the case then we definitely do not want to face the universe as primitive indiginous people unceremoniously discovered by technologically mature explorers.

How did the settlers get to that island then?

Boats, obviously. But the settlers themselves were dead. Their descendants may have had oral traditions about how their ancestors reached the island but I don't think we have any evidence that they constituted a seafaring civilization. Those weren't really possible until the invention of reliable navigational instruments such as the compass.

The first settlers got there by a boat thrown off-course by a hurricane, the the seafaring skill was lost, so communication became impossible.

Fair enough.

That's not really relevant to the analogy.

Or if the universe is a simulation...

... we are either alone in the simulation or we are not.

That's always been an unsatisfying answer, because 1. Its hard to actually test 2. I think its also an artifact of the explosive growth in computing power and AI potential that our civilization has achieved, and is more reflective of that "fad" more than anything.

To me that's far more terrifying.

Why? What's the difference between dying or the simulation just ending?

> or we are not.

not alone? false dichotomy.

"among all explanations to a weird new observation, the least interesting one is true."

What if "we" are both alone and not alone. We are part of some universal life form whose elements prefer to be disconnected from the others for some periods.