Something I have thought about a lot since I started managing people, which nobody warned me about: you cannot tell someone they are underperforming in a way that does not change the relationship permanently. I do not mean they resent you, though sometimes they do. I mean that afterwards, every ordinary interaction has a second layer. You ask how the weekend was and they are checking whether you are asking because you are being normal, or because you are softening something. That layer does not go away when the performance improves. It just gets quieter. I still think you have to do it. Letting someone carry on failing is worse, and the version where you say nothing and then act surprised at review time is the genuinely unkind option. But I have stopped pretending it is a neutral conversation that a good manager can have without cost. It costs something every time, and the honest thing is to spend it deliberately rather than believe the technique makes it free.