People these days don’t own real estate. Wealthy people own it all. Normal people are renting apartments or portions of homes. It’s kind of hard to throw a big party without a big home, a yard, a big kitchen, etc. Small apartments are for small get-togethers that probably don’t register as parties.
Likewise, the larger someone’s home is, the more likely it is to be location in an area with low population density and little to no public transportation. Congrats, you can throw a party, but who are you inviting? All your friends are far away. How can they get there? How long can they stay? Can you accommodate them sleeping there? You aren’t friends with your neighbors who can party easily. You are friends with people on the Internet who are strewn about the world.
And of course, if you live in a major city with lots of friends, small apartment strikes again.
This is part of the reason we have seen the rise of more public events like conventions. There’s a hotel involved. It’s a multi-day event worth traveling to. A lot of people you know will be there. It costs everyone some money, but it’s not out of the realm to go a few times a year. Best part, nobody’s home gets trashed!