Because many elected officials and many voters aggressively try to cut the budget for the judiciary.

As I said elsewhere, if you don't like the system, please call your local, state, and federal representatives and request that they support more funding for the judiciary.

Every case going to trial would cost an incredibly unreal amount of money -- there needs to be some streamlining somewhere, and the question is where and how.

If every case going to trial would cost an unreal amount of money, then the solution is to either reduce everyone's Constitutional rights, or do things differently, not browbeat defendants into a Sophie's Choice between their rights and a 10x-disproportionate jail term.

> Every case going to trial would cost an incredibly unreal amount of money

There are other ways of avoiding the trial than threatening the accused. Also there are countries that don't seem to have this problem. Perhaps a look outside the US might suggest some alternative ways of behaving that might be used.