It's often not that hard. Many routers have a setting for local dns records.
Right, that's easy, but IIRC google devices hard code their DNS servers for casting, so you need to intercept traffic bound for 8.8.8.8.
These folks suggest that just blocking the DNS servers allows you to use your own fallback. Haven't personally tried that, but perhaps more straightforward.
Except on the Linux systems I've used, when I ask it to shut down, it shuts down no matter what. Windows and macOS let programs stop the shutdown process indefinitely (when shutdown/reboot are invoked the usual way).
I think that's what the meme is trying to get at.