Could be a handful or a couple dozen, depends on the person really. Birthdays are more packed.
There’s no real expectation in a party here. Usually you’ll call up people you know from different parts of your life. People bring plus ones so someone from work will be chatting to your family member, a high school friend to someone’s plus one, etc.
That’s usually how people strike new relationships after a certain age.
How many is that? It's comfortable being with people I like, but I just consider that "hanging out".
The appeal of parties to me is it's a social expectation to mingle with new people I otherwise would never have had the opportunity to speak to.