Houseparty shut down by Epic, 2 years after acquisition
gamedeveloper.com
gamedeveloper.com
People didn't want to use it, they didn't see the use for it at the time, and I don't think it ever had enough marketing push to do much of anything.
Downloaded a total of 17m times, keeping in mind much of those aren't real users, or will never make it to the "active user" step of the acquisition funnel. That's almost nothing.