We don’t find evidence of other tech civilizations in the galaxy, because technologies that can manipulate energy at cosmic scales do not construct superstructures around stars. They compactify.
Or they situate themselves just above the event horizon of a rotating black hole. There spacetime spins at nearly the speed of light, and frame-dragging allows for a stable orbit and access to vast energies.
That’s where we find the Hyperopolis. Though it is a megastructure, don’t imagine some futuristic module-assembly constructed like an enormous space station. The Hyperopolis, seen through layers of gravitational lensing, looks to us like tangled veils of chromatic cirrus clouds. How truly alien!
This civilization orbits the rim of a black hole, where tidal gravity stretches an hour of their time into a million years on Earth.
Perhaps they utilize distortions in the fabric of spacetime to monitor distant regions of the cosmos. Perhaps they have taken a millisecond of their time to respond to a primitive tech civilization appearing on our planet.
Some Unidentified Aerial Phenomena may be their portal-views of us.
And what do they see?
Perhaps we are only here because they are looking.