>You can go out and drink and never be legally drunk, much less not drive drunk.
That there is a legal threshold (In California anyway) for being drunk while driving is a common misconception. When you get a DUI, two charges are filed against you. One by the DMV and another reviewed by a criminal judge. If there is an accident, you are found at fault, and you have a ~. 06 BAC, the judge/DA will most likely charge you with a DUI and offer a plea where you get all the penalties of a DUI but may have it officially recorded as a wet reckless. The police also have latitude in what determines being intoxicated. Even if you are well under the legal limit, they can often say that you displayed symptoms of being under the influence of other drugs based on your behavior, your car reeked of marijuana, etc.
Not to sound like a PSA, but buzzed driving is impaired driving, and any level of impairment increases the likelihood of an accident for an activity that humans aren't great at performing even when completely sober.