Same argument applies. Driving slowly for 1km 0.01 under the speed limit, over legal blood alco limit is safer than driving at the speed limit for 10kms just under the alco limit.

It's very easy to come up with thought experiments to show that technically illegal scenarios are not necessarily more dangerous than some legal scenarios.

The law is often made to be easy to apply, not for precision. Hard to see how anyone could see otherwise.

That's not say that the laws are necessarily problematic. You have to draw the line somewhere.