I'm thinking about something like https://kastapp.co where people can do stuff together. It's easier to hang out with other people if there is something to do.
I am also a big believer in the watch party space. Shared online experiences are an undiscovered opportunity in the consumer space. Happy to share more thoughts on this as well!
https://kosmi.io/ is pretty good at co-play and screenshare.
And there's the much simpler https://www.comeover.io/ built on WebTorrent (comes with all the limitations that entails wrt file sizes).
https://rally.video is something drastically different to those, but could very well implement the missing features, I reckon: it'd be über cool to host a virtual School, let alone host a movie night.