This seems awfully cynical to me.
There's a big difference between slavery, and working a job because the money affords your preferred lifestyle or life goals and you've decided that the positives outweigh the negatives. A difference so big in fact that I find it confounding that a term like "wage slave" even sees regular use. I wonder how actual slaves (of which there are more today than at any other point in human history) would feel about such a term.
The two things are so different that your advice to OP is that they should stop. Try giving that advice to an actual slave.
You can choose to work or not to work, it's an option we all have because we're fortunate enough to be members of a society that is mostly civil and mostly good, and work is easier and more rewarding in our part of the world than it has ever been anywhere else, or at any other point in time.
My advice to OP is to find the job where you can have the largest impact, find a cause you care about outside of work, and donate a percentage of your income to it. If it's not fulfilling to you to use that income to live for yourself, you can seek fulfillment in working for a social good (it sounds like that's something you want to do anyway).
Ben Horowitz says you shouldn't follow your passion:
http://a16z.com/2015/05/28/some-career-advice-for-all-you-re...
I think this is great advice with a strong basis in reality. You said you wanted to make an impact and fix things socially? You will do more for that by doing whatever it is you're best at, and using the influence and wealth that earns you to affect positive change socially. Maybe you won't work on it directly, but indirectly your impact will be far greater if you do whatever it is you're best at, whatever that may be.
Personally, I choose to live a frugal life and accumulate wealth. It's going to compound interest over the course of my life, and when I'm gone it's all going to causes that I care about. That's because I could donate $1 today, or I could keep it invested and donate $5 when I die.
I may never actually work on social issues directly, I may not be here to witness my earnings going to important causes, but this is how I'll have the largest impact that I possibly can in terms of doing a social good. Not by doing what I'm passionate about, but instead by doing what I'm good at.
Identify what you want to do with your life, then figure out how you're going to accomplish that by doing what you're best at. Your life can have almost any kind of impact on this world that you want. It's not limited to the scope of your profession, and the size of your impact is limited only by how hard you're willing to work.