Short answer
Train the conversation, not the theory. Managers avoid hard conversations because they’ve never practiced one, they’re worried about damaging the relationship and nobody has shown them a simple way to start. Give them a short structure, have them rehearse it on real situations from their own teams and follow up a week later. Then make sure their own boss has the same conversations with them.
The longer answer
When managers avoid difficult conversations, accountability slips quietly. Poor performance goes unaddressed, good performers notice and the manager ends up doing the work themselves.
Most training on this is a lecture about why feedback matters. Managers already know it matters. What they lack is practice. The skill gets built in rehearsal: saying the first sentence out loud, hearing how it lands and trying again.
This is one of the core skills in our New to the Role and Manager to Great Team Leader programs.