One could also ask why, after more than a hundred years of technology advances, the aviation industry still uses those big, clumsy, ice-prone things called wings to produce lift. There must exist a better way, yes?
Well, as we know, no. I guess the discussion about pitot tubes comes from the fact that they are used to sense a property which is ultimately displayed on an electronic display. Thus people tend to assume that the sensor could also be subject to the same rapid technology evolution as the digital electronics.
But in fact the airspeed sensor sits as the interface between the physical world, which basically does not change, and the digital world.
AoA would IMO be the closest alternative to measure relevant airspeed or dynamic pressure, but as others have said, it seems its benefits have still not outweighed its disadvantages.