Because that’s also what a brain is doing. The thoughts of a housefly may not be very apocalyptic, but there’s an evolutionary path from there to humans, which definitely could be.
"AI" is severely limited in both its inputs and outputs, has virtually no interconnects, but most importantly: it is not a self-sustaining organ. Wake me up when we have implemented RNNs on a dynamic, auto-sensing, auto-actuating FPGA grid.