Where is Everybody?: The Rare Earth Hypothesis

Fermi's question is part of SETI (the search for extraterrestrial intelligence) and led to the Drake Equation.  A variation on this question is the Dyson Dilemma - a space faring people will probably become a Kardeshev Type II civilization and use almost all their sun's output, building a Dyson Sphere or Dyson Swarm and be observable as dumping an astronomical amount of waste heat.  SETI has found no radio signals, no heat signature - could it be that we are The Elder Race for our galaxy?