“2001 - A Space Odyssey” had a good take on this. Once a race becomes intelligent, there is a very short window from the time they transition from biological beings to cyborgs. After than, an even shorter window when they become G-d like entities. So, a race may only be intelligent for a 10-50 thousand years before they don’t care about making contact anymore with lesser beings.
Another theory mirrors “The Time Machine” (H.G. Wells). That is, intelligence can decay and devolve, like the Eloi and the Morlock. Or, more likely, we all catch the liberal disease and go extinct out of guilt and self doubt.
We thought we were going to get the Starship Enterprise but instead we’re getting allah akbar.