isn't a sentient civilization within about a billion light years of us because the signature of Dyson spheres would be unmistabkable and unmissable.
It is entirely possible that advanced sentient civilizations have realized that there is such a thing as 'enough technology', learned enough to permanently liberate themselves from basic needs, and found other kinds of fulfillment and amusement.
It is entirely possible that advanced sentient civilizations have realized that there is such a thing as 'enough technology', learned enough to permanently liberate themselves from basic needs, and found other kinds of fulfillment and amusement.