I think we’re alone in the universe.
Jupiter acts as a galactic vacuum cleaner. I’ve heard that we keep discovering Jupiters in close orbits to other stars, not as good of a place. BTW, other stars are mostly red dwarfs, unlikely to have habitable planets.
The tilt of the earth gives us seasons, and the moon stabilizes the earth.
Our civilization has also been lucky: some great luck paired brains (why develop brains? it's not an inevitable march to brains but to appropriateness to the ecological niche) that can speak and learn to read, with opposable thumbs, and not underwater. We have iron near coal near good waterways for easy transportation (but not everywhere on earth!), communication between civilizations at the same latitude (otherwise, far slower technological development), pack animals like horses, and a large quantity of fossil fuels, though maybe the fossil fuels are inevitable with life?
I bet there are some lucky things about the dinosaur extinction. Timing, severity.
Our civilization continues to be lucky. If your planet is too big you can never escape it. We only get 4% of the mass we shoot up in rockets, but it means we have a very big planet that we can still escape from.
I haven’t read it, but there is a book "Rare Earth: Why Complex Life is Uncommon in the Universe" by Ward and Brownlee on this subject.
Fun: Life may have taken more time to evolve to humans than the age of the earth: https://phys.org/news/2013-04-law-life-began-earth.html
How did that go again? "All these worlds are yours, even Europa."