For me it is worth it to host a password manager for me and my family, although I just did a one-click install on Digital Ocean (using Bitwarden, not Vaultwarden ... so far).

To me (and I'm pretty ignorant about this stuff), the biggest weakness of a password manager is that it's the one link in a chain that somebody needs to break to have all of my passwords. Hosting that at bitwarden.com or lastpass.com or whatever makes it an even sweeter target because those are known targets. At least self-hosting makes it more difficult for somebody else to find my password manager.

Moving to Vaultwarden has its complications but it would also be fun, and maybe a cool project for the kids. And like you say, if we screw up and they lose their instagram password they won't even remember the pain once they've all grown up and the world is a dystopian nightmare of climate catastrophes, wars, etc. They'll be busy looking for the fattest grubs to eat.

We like to host stuff :) If I am faithful to myself I might be paying more than I would if I wouldn't self-host

You shouldn't feel bad about that, because that money isn't lost, you just used that money to buy enjoyment which is valuable as well.

And that is without even accounting for the amount of knowledge and experience gained by self hosting.