You could stand one up and your parents join it? Yes, not everyone can stand up their own self hosted stuff. In fact few of us can. There's a huge missing gap between your phone/desktop applications and just installing and running hosted applications, but I digress.

I stood up a Mastodon instance and invited a bunch of my friends. Only like 3 of us use it, but it's up and connected to the greater Fediverse.

No need to go that far. Maybe one HNer even does that or even wants to do it.