I suspect there'd be a strong selection bias where the only people who'd continue to drive manually would be the better (or at least more attentive) drivers.
To enforce that, you could make the licensing regime more like an FAA private pilot rating and less like a token ritual for access to your God-given right to drive no matter how incompetent.
To enforce that, you could make the licensing regime more like an FAA private pilot rating and less like a token ritual for access to your God-given right to drive no matter how incompetent.