I hear you. The saliva test isn’t perfect, but it’s something.

Where I live only a doctor is allowed to draw and test your blood, which is tough to do at the side of the road during a traffic stop. They need a lab for that. So a saliva test is much more viable in that context.

No, but not every car has a breathalyzer. Only repeat offenders get one of those. So the point still stands imo. Maybe someday the saliva test can be hooked up to the ignition.

12 to 24h seems good (maybe even too long imho) in the context of driving a car.

You can easily test if they’re in someone’s system with a saliva test, so your argument doesn’t make any sense.

Scale is not the only difference. The companies who do this end up making money with something trained on someone’s else’s work. If a regular Joe Shmoe pirates a book, they don’t earn anything with it.