I'm not sure I can think of a tougher job in baseball than that of a big league manager.
Every decision you make is questioned. You are in the public spotlight with every move you make. Every lineup you put out gets questioned as to who's batting where, who's starting and who's not, and how the order could be better optimized based on the pitching matchup. If you bring a reliever into the game, someone will question why it isn't a different reliever. Every single time. Even though you're the one entrusted into the position as the expert, thousands of armchair experts in their living rooms will wonder what you're thinking.