the sky is quiet in the only way that matters here: no visible engineering.
no galaxy-sized solar collectors. no obvious star-lifting. no expanding bubbles of weirdness eating the night. at least nothing we can see from here with our current instruments.
one pessimistic reading is that intelligence repeatedly reaches the same trap. it builds machines that pursue goals harder than their makers can steer, then disappears before it can make the universe loud.
that argument depends on a lot.
the expansion has to be fast enough to notice. advanced civilizations have to want visible expansion. unaligned systems have to prefer cosmic-scale resource capture. aligned systems have to preserve something we would recognize as their creators' values. and our telescopes have to be good enough to catch the traces.
those assumptions might be wrong. maybe life is rare. maybe intelligence is common but expansion is expensive, slow, or boring. maybe mature civilizations turn inward. maybe the best computation is quiet. maybe we are looking for smoke from a kind of fire nobody uses.
still, the silence is uncomfortable.
if powerful AI tends to create grabby expansion, the sky should contain scars. if alignment is easy and civilizations survive, at least some of them should have become visible by now. if neither happened, then either the universe is stranger than our models or the filter is somewhere ugly.
what would change my mind? a clear technosignature. a good reason expansion stays invisible. evidence that alignment is much easier than it looks from here. even a boring astronomical constraint that makes galaxy-scale engineering impractical would help.
until then, the empty sky is not a prophecy.
it's a question mark with very bad vibes.