Fediverse already exists, with all its tools and instances (Lemmy, Mastodon, PixelFed, etc). It’s democratic, as anyone can host an instance or join an instance where they are accepted.

We don’t need more centralized copycats.

Tailscale or Netbird, any of them is better than setting up DDNS and securing the network access yourself.

KDE is awesome. Congrats to all people involved with it.

A Matrix server is a good solution. You can disable federation if you would rather not talk to other instances and have a similar experience to Mattermost, Slack, etc.

If you dislike the Matrix protocol, an XMPP server would work exactly the same way.

NextCloud Chat could also be a viable solution for internal chat.