We are far past that point. So many critical systems are running on autopilot, with people who built and understood them retiring, and a new batch of unaware, aloof, apathetic people at the helm.
There's no real need for some Bad Actor -- at some point, entropy will take care of it. Some trivial thing somewhere will fail, and create a cascade of failures that will be cataclysmic in its consequences.
It's not fear-mongering, it's kind of a logical conclusion to decades of outsourcing, chasing profit above and over anything else, and sheer ignorance borne of privilege. We forgot what it took to build the foundations that keep us alive.
That's just what old people like to think: that they are super important and could never be replaced. A few months ago I replaced a "critical" employee that was retiring and everyone was worried what would happen when he was gone. I learned his job in a month.
Most people aren't very important or special and most jobs aren't that difficult.
