Most people don't actually want to hurt their coworkers. But the reason lockouts are actual physical locks, is because people can get confused, make mistakes.
You give everybody doing the dangerous work a physical key to a specific lock on the device that can kill them, so they all have to come back and unlock it individually before you can enable the machine again.
Prevents issues like a work crew leaving a site piecemeal, and then the first guy thinks the last guy is done, but the last guy ran back to grab something....
And if this industrial panel doesn't have the ability to be locked out, you lock out the f****** electrical panel and cut power to it.