The 0.08 BAC limit also has no basis in reality for what impairment is. It's a political reality, not a scientific one. MADD and other organizations lobbied to make this a legal limit across the US and many other jurisdictions around the world followed suit.

That's not to say that anyone should drive after drinking, but the basic reality is that impairment is often individual, and cannot be directly measured by blood alcohol content. Many people are impaired with a lower BAC than 0.08, and in many states you can now be charged and convicted of DUI even if your BAC is not beyond the legal threshold on the basis of purely circumstantial evidence.

There's no good answer here, because we need cut and dried evidence in our legal system to prevent abuses, but there's not really good ways to do that. Separately, the leading cause of accidents is no longer drunk driving in most parts of the West, it's inattentive driving due to cellphone/electronics usage while operating a vehicle. Younger generations don't drink as much as older generations, to the point that zero-percent alcohol spirits and NA beer are now becoming broad markets and it's dramatically affecting bar/pub culture, but younger generations nearly as a rule are addicted to their smartphones.

We've also become a lot better at distilling high-proof alcohol, and at making it cheap enough that most people have the budget to get absolutely wasted on the regular.

Most people don't do that, but the option is there for anyone looking to make their life and the lives of people around them significantly worse.