I try to articulate this idea but I keep getting bogged down in details or getting lost down tangents. So let’s just dive in and see if we get to the other side.
It’s about Humanity… Hmm, I should say sentient life to be accurate. Humans just happen to be the species I’m aware of. But, I’m kinda starting at the end here so we should back up. We need to talk basics, which means physics.
Gravity makes the solar systems an inevitable fact. Mass attracts mass, it creates stars which burn and heat the planets that formed from the accretion disc surrounding the stars. It’s neither chance nor up to the discretion of some higher being; the planets and stars will form. Physics makes it so.
And likewise with biology. We may not have evidence of life on other planets but there doesn’t appear to be anything special about earth. It’s extremely likely that life will happen when it’s able to. Replicating chemical structures become persistent by adapting to changing environments. They are resilient because they adapt to their environment, while also maniputlating that environment. On a micro scale, it’s very, very hard to wipe out life on earth.
Sentience/consciousness is a byproduct of the mind. It’s maybe not a necessity but it’s very useful to the creature in question. That’s a variable, but what is a logical progression of physics is Memetics. The same way self replicating chemical structures persist in surviving, so do mental replicators. Where larger animals exist, minds exist, and where minds exist, the ability to learn will be hugely important. The first species to create internal memetic structures in their mind will dominate their planet (whether it’s good for the animal in question is debatable). Communicating thoughts to other minds, whether through sound or writing or even some form of telepathy, will create a new branch of evolution. The Meme.
Our growth in technology, in power, is Memetic. Therefor, it is an inevitable conclusion of the universe. Another step in the progress of the universe. It is not the “purpose” of the universe though. One must not fall into the trap of egoism, we are not the endpoint. Merely the furthest step we’re aware of. The universe will always be far bigger than our meager rock.
It is also not to say we will continue to our currently imagined future. We may not have found evidence of life because it never breaches the light barrier. Given that limitation, it’s incredibly unlikely to create any civilization larger than a solar system. Communication is nearly impossible from one habitable planet to the next. So most life lives and dies on its homeworld.
Some would say it’s sad to accept that. But really, it’s the same as accepting your own mortality. The earth is mortal just the same.