As others have said the intent is not to document sobriety but to have a subjective reason for an arrest which looks good in the scorecard.
Look for “if cops say I smell
Alcohol, say these words” on YouTube, gives you tips on how to respond if asked about alcohol use or doing a sobriety test.
Look for “if cops say I smell Alcohol, say these words” on YouTube, gives you tips on how to respond if asked about alcohol use or doing a sobriety test.