I use the 'In Vino Veritas' phrase to remark on instances where a bit of disinhibition allows one to come to a correct conclusion by way of letting go of a bunch of bullshit performative social norms...

... but yes, the flip side is that excess and addiction can absolutely warp a person, not 'reveal' them, and that your baseline inhibitions, to some extent, fundamentally are you, are your characteristics, your personality.

And, people often say a lot of very objectively stupid bullshit when drunk as well.

But but... a person is also to a good extent... a process, an evolving system, not a fully static thing.

As to your example... a person who only hits on someone after a drink or two likely just has less self-confidence than a person who hits on other people often.

But that does not mean that our ... liquid courage needer... that they cannot gain self-confidence by other means, by maybe going to a bit of therapy and learning how to be reasonably proud of themselves, removing toxic, negging people from their life, engaging in self-affirming activities, reframing their view of themselves and their place or part in the world.