Yes, massive, but because of the unique mentality and system of values of engineers/nerds in general we are focused on solving technical problems and learning new things while the rest (management, RRHH, sales, etc) are focused on status and getting a bigger piece of the pie for themselves, so we get f*cked over by them very easily.
>How could we increase our leverage?
1- The single most powerful tool we have is fully sharing salaries and compensation. That drives prices up (and other benefits such as vacation time or equity).
2- Forming common fronts like low skilled workers do in unions or other associations that set minimal working conditions that avoid races to the bottom and exploitation (60hs work-weeks for example). In my third world country companies do this themselves and group in something called a "technological pole" that is just a gathering to cap salaries and avoid competing among themselves. So, they later threaten you that if you quit you would be black listed. (This resulted on a massive migration of engineers to other countries and to freelancing on the internet, they were short-sighted and not very smart :D ).
3- Tribalism. Start to see the rest of the other roles like they see you (management, RRHH, sales, etc). Other tribes competing for the same pie and act accordingly. Stop going along with the "you should improve your soft skills to make our job easier" and flip the tables and start to demand that they become better at a technical level to make your job easier instead. We are in high demand, they are not, simple. Make them work harder and learn to speak to us and adapt to us instead of the other way around.