No, I don't think Earth or the solar system are something unique in the universe.
From the first paragraph I understand that with humans you mean intelligent humanoids, right? Or maybe not even humanoid creatures but living beings that are somewhat similar to us in the sense that they can create complex societies and have reached a similar technological development as us.
If that is the case, I'm not disagreeing with you.
It's possible that we could find societies similar to ours even in our galaxy.
But again, this is all pure speculation.
We can only observe and study evolution on our own planet. Maybe life in other planets is not even carbon-based, and even if it is who knows what creatures might pop up into existence in different worlds. Maybe we couldn't even think of something similar in our wildest dreams.
Assuming the universe is infinite though, somwhere there has to be a planet identical to ours where everything is the same. The opposite should be statistically impossible as crazy as it seems.
So, there may be humans living on another planet. Maybe not in our galaxy, maybe not in our observable universe but somewhere.