How else to learn humble, team-oriented, potentially uncomfortable honesty but regular practice?

Psychological safety is the biggest factor in overal team performance and morale. That safety comes from trust, and that trust comes from routine demonstration of vulnerability and support.

Lone wolf rockstars can have their own moments of self-defeat and wheelspinning too. But if they haven’t developed a sense of courage and humility to admit it and bring it to the team, then the whole team is now literally bottlenecked on their ego.