A common mistake from more senior engineers is that they continue to assume that the manager is an authority figure.
This is often the case, but doesn't have to be. David talks about a case in his past job where an IC on the team was more senior than him as the manager. And the IC engineer was objectively more important to the team, indicating the value of this senior-level person not only to getting work done, but also setting direction and giving feedback to others.
Senior engineers should view the relationship with the manager as a partnership rather than a person for whom they must follow orders. The tech lead and manager have different but overlapping responsibilities in helping the team succeed. Realizing this unlocks a more fruitful collaboration.
Remember, managers will frequently have blind spots that a tech lead can point out. These insights and observations may manifest in actually pushing back on the manager's plans or strategy. This is a role that senior engineers should embrace.