Back in the 80s/90s, when my grandma was alive, we used to have big holiday dinners for the whole big family (I think in total of 10+ people) in her small apartment (about 20 m^2, perhaps even less). It was extremely crowdy and some people used to eat standing outside and chat with each other. But it was also one of my best memories.

30+ years forward, I moved to a new country, and we only have one kid. We haven't had this kind of big dinner for decades since my grandma passed away in the late 90s.

The families are getting smaller and more atomized, so only people who are VERY into big dinners throw them.

This is a good point.

I am retired now and lucky to have my (now adult) children living nearby. Every Friday I cook a large pizza dinner for everyone, their spouses, and their children, and any friends they want to invite. I will always be an introvert, but this weekly meal is the highlight of my week.

The difference between this and what my parents did is that I host for my own pleasure and for what it does to bind the family together. I don't expect reciprocal invitations, and no obligation is ever implied (I hope).