"The Dark Forest" by Liu Cixin is sci-fi, but I don't think it's too hand-wavy. It presents a pretty logical answer to the Fermi Paradox, based on a couple obvious axioms.
Wikipedia article: https://en.wikipedia.org/wiki/Dark_forest_hypothesis
Dark forest is way down at the bottom of "plausible explanations"
It just sounds like it makes sense for 3 min then it really, really doesn't
Taking the (original) dark forest problem and applying it to civilizations in space sounds like a Strawman problem
(you can also think about all the technical hurdles such a thing would take, also remember that the fast something goes the harder it is to maneuver and to stop at the destination), don't underestimate all the kinds of noise that such thing will create and can be traced back to its origin.
- No species on Earth do that kind of unprovoked attack, unless it is very cheap and quick (and riskless)
So no, I think there are many better explanations than simply the dark forest one
How would you do that? There's a tremendous amount of energy already in it, it's releasing it gradually for now but what if there were ways to make it release all at once? One potential approach would be to throw something at it at relativistic speeds (you'd imagine accelerating things to near-lightspeed would be a pretty obvious milestone in the tech tree).
For an advanced civilization, this is pretty easy; they'd probably be able to do it routinely from a mobile spaceship so they don't have to give away their home star's position.
If you read the books, you'll notice that they talk about "hiding gene" and "cleansing gene"; these are traits that civilizations acquire as they evolve.
I think that this has real-world implications in terms of how we conduct our SETI (search for extra-terrestrial intelligence); we should be careful of our radio emissions and things like sending a powerful signal / message to another star should probably be avoided.
The simple fact of the matter is that there is no empirical evidence for life outside of Earth. My guess is that it exists out there somewhere, but there's no good basis for believing that life is as common as the Dark Forest hypothesis requires.