Those ideas would both lose valuable aspects of the buses.
Uber/Lyft/cars would have a much bigger impact on traffic on 101, which is already terrible congested during rush hour. The buses help to minimize the impact of commuters.
Public commuter options eliminate some of the convenience for two reasons. First, Google has a single destination for everyone which reduces commute times. As you increase the number of destinations, you increase the possible routes exponentially, making it much less feasible to have direct routes everywhere. Second, you can't do confidential work when on public transportation. So you would be much more limited in what you can accomplish during the commute.
Uber/Lyft/cars would have a much bigger impact on traffic on 101, which is already terrible congested during rush hour. The buses help to minimize the impact of commuters.
Public commuter options eliminate some of the convenience for two reasons. First, Google has a single destination for everyone which reduces commute times. As you increase the number of destinations, you increase the possible routes exponentially, making it much less feasible to have direct routes everywhere. Second, you can't do confidential work when on public transportation. So you would be much more limited in what you can accomplish during the commute.