I'm saying it can be enforced the same way it is in most industries that rely on dangerous equipment: via insurance policies, civil lawsuit, and criminal prosecution for negligence.

We don't breathalyze pilots when they board the plane, despite them being responsible for hundreds of people at a time, and millions of flights complete every year just fine.

No one suggested doing mandatory DUI checks except you, in order that you can argue against regulation. Regulation is requiring the pilot to be sober. Mandatory breathalyzer checking would be an example of a type of enforcement (which no one is arguing for).