Most people I know that say the whole "I like being in control" have only drank a few times (maybe bad experiences) but like the idea of not drinking so they promote this narrative in their head. It's an excuse so they can compartmentalize drinking into the "Now I don't have to care about this because it's bad for my physical health anyway" box.

Really it's just an easy excuse that doesn't need to be true because the fact remains that this person doesn't want to be a person who drinks and most won't question it.

It's also possible they get drunk quite easily.