You basically described all the advantages of public transit. And in fact fully automated vehicles are actually not that uncommon among public transit systems t

You basically described all the advantages of public transit. And in fact fully automated vehicles are actually not that uncommon among public transit systems that operate on fixed guideways (most recently Skyline [or HART] in Honolulu). The only problem with a public transit system that gives you all of these advantages is the expensive infrastructure and operations required. However compared to everyone waiting for the tech to arrive (which may never happen) and then buying and maintaining a very expensive and bulky machine, building and operating a good public transit system using common funds is actually orders of magnitude cheaper, and far more economical.