So, the short version = if you want to be a real lawyer you need to go to a T5, or do above median at a T14. Otherwise you're a glorified paralegal?
I'm not going to take issue with that suggestion, but will ask yet another question: exactly how do they (the law school collective) attract 40,000 new matriculants (or more) each year?
It depends how you define "real lawyer". If real lawyer = Biglaw, then you need to be even better than that, at least right now- pretty much HYS, or median or above T6, or top 25% of so MVPB, or top 10% the rest of the T14, or top 5 (not percent, but people) at other schools. But there are a lot of very good jobs outside of Biglaw- government jobs are hard to get as well, but not quite so hard to get. Beyond that, there will be people who "make it" in law, but it's a crapshoot, and the odds are against it.
As for why there are so many law students- it's probably a good thing, because there's a lot of repetitive and time consuming legal tasks, so lots of lawyers keep the costs lower than they would be. But lots of people delude themselves into thinking they're going to make 120k+ straight out of law school. Unless you're T14, don't count on it.