It always surprised me when people talked about their Bosses / Managers like they were some sort of gods that were going to save them and protect them from all bad things in the world.
If there is no protection for the employee no one would get into a dependent employment relationship in the first place, especially when the pay is universally worse than being self-employed.
Most of the managers that I worked with opened up our first conversation together with how they "care about people and their careers".
Now, intrinsically, the job of a manager is to serve the company by serving those they manage. They do this by enabling workers to do the work that needs to be done. A middle manager is supposed to represent his team to upper management. However, too often, middle management is more interested in schmoozing with upper management rather than standing by their team. And if he is too difficult, upper management can just replace him with a more compliant manager who will function as a faithful messenger and nothing more.
So, there's no structural way to ensure these things work. Culture and personal virtue are necessary.