I have been a part of many organizations as an intern or a full time employee throughout my bachelors and post grad. And in every organization people management has felt like a spine of that organization.
I believe People management is more important for a business than immediate revenue generation. If a company/ business/start-up doesn't hire the right kind of people for their organization and doesn't invest in training them, making them feel valued by giving due credits and also when required showing where improvement is needed, that company is bound to be shut sooner or later. One good example that I can think of is Kodak- where issues like lack of employee engagement, poor leadership, and failure to adapt to changing market conditions contributed to their downfall.
An example where a leader took responsible decisions and understood their employees needs to suceed and remain is business looking at much greater profits is " Gravity Payments", and "Microsoft".
In my last organization, I worked with a lot of cross functional teams and there were times where the team manager would blame the team and deflect the responsibilties. In my humble opinion, along with Encouraging and empowering workers, Listening attentively to the team, Resolving conflicts, flexibility, clear communication, patience, organization, and trust, the ability to take responsibility for the teams actions is also a key component.