They can, but the setup is still non-trivial and full auto landing capability isn’t used all that much even if technically available. It also isn’t just the capability of the aircraft, it requires a shitton of supporting infrastructure on the ground (airport) and many airports don’t support this.

That would be equivalent to installing new intersections where you’d also have a broadcast of what the current signals are for each lane, which would help self-driving cars immensely (and regular cars eventually too, with assistive technologies to help drivers drive more safe), but that’s simply not a thing yet.