I was in the same situation, bored out of my mind working on a product that *nobody* cares about, let alone me; The product was mature, so there was very little development. Coming in to work was getting to be a major drag. I was starting to consider changing careers entirely, thinking I was a burn-out.
Fortunately, a new project popped up at work, and I was lucky enough to be on it, and it has definitely improved everything. I am having fun cranking out code just like "the good old days", so the burn-out thing was really just boredom, and knowing that the work I was doing was never going to affect, well, pretty much anyone.
So perhaps the question is, "How do I get onto a new project?"
Maybe it won't happen with your "manipulative jerks".
Maybe you have to come up with something completely new.
Are there other devs there too? Or other people who like to come up with product ideas?
I think I was pretty lucky. You may have to make your own luck here.