Consumer cameras mostly use CMOS (Complementary Metal Oxide Semiconductor) chips as detectors
CCD cameras for astronomy: much smaller market, so much more expensive per pixel
CCD (Charge-Coupled Device) is more power-hungry and needs more off-chip circuitry
The advantages for astrophotography are:
Personally, I have felt no need to get a CCD camera. The only thing that might persuade me is the monochrome option: not having red, green and blue filters in front of the pixels opens certain possibilities.
My ideal would be a conventional CMOS camera without the colour filters. Leica have produced one but it is very expensive because of its limited market.