Re: "...and a more powerful computer."
Your examples are all part of a car driving itself with no passengers at all, which is probably way further off than a self driving car that is carrying passengers who could themselves lookout for the roof coming off and enact an emergency button.
A modern car today with relatively little computing power has sensor all over the place checking your emissions, tire/tyre pressures, temperatures, pollen ingress, distance from other cars, current speed vs revs, dpf state, multiple temperature sensors. Generally a modern car can tell if something significant is wrong before you do.
There are currently driverless trains which have to have a certain amount of sensors but don't have a compute that is amazingly powerful. Your house could catch fire, have an aircraft hit it, have a gas leak, have the electrics cause a potentially fatal injury, have a balcony fail etc. However we don't need to have sensors all over the house - just a smoke alarm, and some failsafe breaker switches generally suffice. In fact more sensors (IoT) are generally frowned upon.
All the (albeit understandably) scaremongering comes from the idea of an out of control or runaway car. However that happens with vehicles today, it's just so rare that it is dismissed.
Biting the hand that feeds IT
