Please post the link to the video before we can discuss. Most of the videos are nothing but conspiracy theories.

A NAS, a router or Storage server all of the are computer. Just use old computer as nas instead of throwing them away.

We should be careful after looking at what happened with XMPP

It’s great that you self host but security especially of service directly exposed to internet is very difficult. Use somekind of Direct VPN or services like tailscale etc