Not an American thing where I am, I have five 20 something’s with very large active friend groups, multiple ones. HS friends, college friends, work friends, when they come home I regularly have literally dozens of friends at my house, the night before thanksgiving there were 50 of them here. Now that they’re all adults their friend groups sometimes combine and they all go out together (I do have 2 living down the shore in NJ so summers mean a lot of socializing).