Aside from wanted to rely on cops/ambulance on any emergency that happens after two drinks, you are assuming that the system works well in nominal cases, and won’t have specific bugs that will prevent driving in otherwise ok circumstances.

For instance alcohol sensors used by cops need to be recalibrated every so often. Even less sophisticated systems like tire pressure on modern cars work well most of the time, but will fail and need repair at some point. These sensors used to check your intoxication status will fail and you might not be able to drive your car to the repair shop. Or worst case scenario they fail because you are in problematic situation that triggers the false alarm and you’re double stuck there.

Overall I don’t see a track record that warrants us to be optimistic about this working as well as we want to…