I wouldn’t necessarily say it fixes problems and if it does it certainly isn’t free of cost in more than one way. I do think it can temporarily lessen some anxieties that one might view as obstacles to happiness because they impede one’s ability to engage in meaningful social interaction. I also think that making friends and finding romantic partners are learned behaviors that you need practice to get good at. If alcohol can help you be social enough to make friends in a new place or find a partner then I can see why someone would say it fixed a problem for them. It’s certainly more expedient and cost effective than therapy to get past your hangups would be.

That said, that sort of “responsible” use of alcohol isn’t without its drawbacks and risks. I don’t know how common it is either. Perhaps that’s just what people who like to drink tell themselves to avoid feeling shame about their behavior.