Your friends are pretty likely to show up.
If you invite virtual strangers, they probably won’t show up.
People these days tend not to have friends. They have “connections” on social media. Those people don’t care about you.
Nothing about invites or confirmed replies. I don’t need this. Most moms would love to take their kids to one. Combines babysitting with socializing.
We're all disconnected from each other. So there's a lack of community. Notable exceptions? Religious organizations. If you're a Mormon, you're not going to have this problem.