That's the kicker.
We think humans are so advanced, when in reality i doubt the instruments we use to measure things in outer space are accurate enough to pick up anything outside our realm of basic knowledge.
I think there are many things far more advanced than us that are not so far away. We just haven't learned how to comprehend their existence or even measure it.
On a galactic level, i doubt we have much understanding of how this all works. We know what we have discovered, but i have a hard time believing we fully understand life, biology and even chemistry outside our world. Even what we know of on Earth, may not be as accurate as we think it is.
This is about where I am with this stuff - that of course based on our current understanding this stuff can feel outlandish, but as I think others have mentioned in this thread, imagine trying to explain x-rays or radio waves to stone age humans...
So once you start conceptualising things like the Alcubierre principle, or uncoupling from the Higgs field, or quantum entanglement/disentanglement, who really knows where we will be in 200 years time...
If people are familiar with the element 115 angle to the Lazar story, this guy develops quite an interesting take - that galactic neighbours just might not be that interested in us due to the paucity of heavier elements in a stable state in our (relatively) young solar system - the more exotic 'good stuff' is found in the older systems...