Which happens because of power prosecutors have (ability to decide charge which makes all the difference - plea can make difference between a year and risk of 30 years in prison) which has little to do with jury vs judge. Majority of defendants deciding that they don't want to risk (or cant afford) a day in court is not an argument for that system.
His argument was that juries prevent "arbitrary court system to throw people in jail who are innocent and removes other protections like jury nullification". There is nothing observable that would confirm that.
They don't do that, they prevent pretty much nothing.
It says nothing one way or the other because the system isn't being used in those cases.
Put simply, if you want to make claims about whether jury trials or bench trials put more people in jail wrongfully by citing US incarceration data you have to somehow contend with the fact that the vast majority of cases don't go to a trial of any kind. Or at least have an argument as to why switching to bench trials would change that circumstance.
