Surely there are some people who are simply unmanageable?
There is a cruel irony in that. It has a bit to do with them, not much to do with you, and a lot to do with the environment. The problem with focusing on people is that it becomes reductive very, very quickly.
You can use psychometric testing, or dig into their private lives and work history to try to work out why people aren’t performing. But there are things you'll never know, and things they'll never tell you. So, there are limits to what you can manage.
However, under the current management paradigm, what gets measured gets managed. And what you can manage defines you as a manager. So, if there are limits to what you can manage there are clearly limits to your ability as a manager. There is something deeply unfair about that, made worse by the fact that there’s a good chance you are one of these disengaged employees yourself.
The numbers aren’t good for middle managers, and on top of all that, you’re expected to fix it. However, your people – despite their engagement or otherwise – are not actually the problem. They’re just symptoms of something else.
I realise that sounds harsh but you’ll keep trying, keep failing, perhaps slowly get better at managing people, but still end up spending hours every month putting Band-Aids on wounds that need excising. In other words, a lot of effort for not a lot of gain.