“Such civilizations would need to last for at least 280,000 years to coincide in time with humanity.”
Austrian Academy scientists calculated that if technological civilizations exist in the Milky Way, the nearest is probably 33,000 light-years away. They’d need to survive for 280,000 years to overlap with us. This is the Fermi Paradox with numbers attached. Even if intelligent life is common, the timing and distance make contact essentially impossible. We’re probably alone in any practical sense, even if we’re not alone in principle.