Together with France, Italy is the motherland of high quality wine. It doesn’t have to be expensive, take the Prosecco for example. To have fun, the Italians won’t bother drinking “foreign” beverages like beer, cocktails, etc.
Beer indeed is the default drink with pizza and is produced also in Italy by famous brands like Peroni.
You have binge drinking in Italy, especially by youngsters, and being able to stand huge quantities of alcohol is a pride also for some adults. Especially in the weekend, the police routinely checks the car drivers, pressing DUI charges if this is the case (in Italy you won’t be arrested, but you will temporarily lose your driving license and you will be summoned to Court).
In general, however, you will get the impression that binge drinking during the weekend is much less widespread in Italy than in other, more disciplined European countries. This could be because binge drinking requires cheap low quality alcohol, and Italians don’t like low quality food or beverages, ever.