Wow! I'm sorry you had to go through this. It sounds like a really toxic department culture and like things really sucked. I haven't posted or visited this place in maybe 8 years since I was applying to grad school but this post made me want to share some thoughts. I've now finished my Ph.D. (at a top USNWR 5 place) and am now an assistant professor at a very nice place. Yes, I got very, very lucky and my experience is not representative of the typical applicant. But here are some thoughts:
1. I picked dissertation committee members based partly on their not being jerks. I did not work myself to the bone. Mostly, I worked the equivalent of 9 to 5 hours. Nine hours of real productivity and focus (i.e. with absolutely no internet, email, etc) is probably more than enough for most Ph.D. programs. The tough part is getting that focus. There are exceptions of course: when there was a tough game theory problem set due or the last frenzied two months of dissertation writing.
3. I made sure to give myself options. I came into grad school a qualitative scholar and left with some hard data science-type skills and I worked hard to hustle some consulting gigs. I don't really agree with the previous posts about consulting (at least after coursework is over).
4. I am not sure what field BigTenPoliSci is in, but to me the description of a star-focused job market sounds more like American politics and less like Comparative.
I wouldn't try to actively persuade anyone to go to graduate school, given the probabilities involved, but at the same time if you want a lottery ticket to the TT and you have a funded offer from a place in the USNWR top 10, you're probably not making a huge mistake.