A VPN can’t protect a connection that keeps dropping because of a damaged patch...

https://zandersexcellentblog.quillnesty.com/posts/why-running-cat5e-now-can-mean-ripping-it-out-in-five-years

A VPN can’t protect a connection that keeps dropping because of a damaged patch lead. And a switch left on default credentials can give an intruder a path across the network