Lao Tzu said that the sea rules the rivers by lying below them.
This effect is visible in how the legislatures of the British colonies in America slowly usurped power from the royal governors, by gradually taking over governmental responsibilities. They turned the governors into figureheads.
In the modern day, the effect can be seen in situations where secretaries manipulate the institutions they serve by setting schedules, making contacts, keeping records, and sundry tasks that the executive delegates to them without looking too much into their execution. Josef Stalin's example as the Secretary of the Soviet Communist Party is the most famous, yet monarchs throughout the ages have been subject to this phenomenon, as their daily lives follow the course set by their senior court servants, scheduling them for one court function after another.
The boss does not look into their secretary's business very closely. A lot of them don't even know what to look for! Stenography, shorthand, spreadsheets -- clerical stuff. Those tasks fall to secretaries because the secretary knows how to do them on a consistent basis, where the boss does not. That is why the clerical profession exists -- to handle the details. All that matters is that the work gets done.
This phenomenon is also visible in the role of janitors, who have an overlooked mastery of an institution's physical environment as secretaries have an overlooked mastery of the administrative portion. The boss does not wish to look too closely into the things their janitors deal with, especially not if they involve odors.
Nor does the boss have any idea what to look for when it comes to janitorial work. While they could do secretarial work on a slow and faltering basis the skillset of a janitor is entirely outside an executive's business.
In all cases, people who are delegated many tasks along with great autonomy in their execution, are effectively granted great power within their environment, whether or not their senior authorities realize it's happening. This effect is diluted with increasing numbers of employees in the same position; in such cases institutional power is a collective function of the department. If the employees of the department do not coordinate on how they influence their institution then they let their power lay dormant.
The people who are handed many tasks, but little autonomy in their execution, are drudges if they are paid, and slaves if they are not paid.
Therefore if you are receiving responsibilities, and you grumble about being a drudge, consider what autonomy comes along with those tasks, what effect those tasks have upon the rest of the institution, and how many people are in your position.
Are you one of many in your role, being told to follow a specific set of methods according to a specific timetable for the sake of producing specific things? Then you are a drudge. Are you alone or of a few, told to simply get the work done, and the work is about supporting the institution's structure? Then you are an overlooked executive –
Though never paid as well as the boss. The boss needs a high salary in order to pretend they're the one in charge. Rank must have its privilege. And if you're alone then you can't exactly form a labor union out of one person. You either have to negotiate openly, alone, by arguing your singular irreplaceable value to the institution, or manipulate the institution very quietly –
And if you find yourself unchallenged when you manipulate things meant to be the boss's final decisions, why then, you've usurped all effective control! This is how palace major-domos rule countries from the shadows. On TVtropes this is called the "Almighty Janitor," though one wonders if a janitor could do such a thing effectively.
A secretary seems like they would have more opportunity. Especially if they control who gets to meet the boss. If someone is turned away, well, the boss doesn't need to know about them, nor see the email requesting an audience.
Heed the lesson of the Soviet Communist party, and always be wary of your secretary.