"because it creates a much easier environment for an arbitrary court system to throw people in jail who are innocent and removes other protections like jury nullification. You could look at Japan, which tried to solve its problem of innocent people going to jail by introducing a lay-judge system (kind of like jurors who can ask questions during the trial), for a real-life example of some of the problems you might have."

Practically, united states of america have biggest incarceration rate in the world, one of the most expensive legal systems (if not most expensive) and quite long sentences compared to other western countries. Jury nullification is basically never used and majority of jury members don't know about it.

I am not saying that other countries have flawless awesome court system, definitely not. But I have yet to read something that would convince me that jury is better or at least worth additional expenses.