IIRC, a commercial pilot cannot consume alcohol for at least 8 hours before a flight. Some airlines it’s 12 hours.
You would think an ATC would be the same regulation..............
We have a friend who is a commercial pilot. Rarely do you seem him have any alcohol, even though he offers it to his guests. If you do see him drink, you know he is just got back from duty, and has a few days off before he flies again. He’s a great guy. He takes his job and his responsibilities very seriously.