Plea bargaining, for better or worse, is a uniquely American invention the rest of the world does not share.
Committing naughtiness level 5 on a scale of 1 to 10 crime in "EU" and in "USA" and you'll get a punishment of X years for a level 5 conviction in EU. In the USA you'll get a plea bargain offer of X years for agreeing to be guilty of a level 3 crime, or you can take your chances at a trial for a level 5 crime (with admittedly draconian punishment). About 90% to 98% of criminals take the plea.
The widely advertised injustice is that on paper, a level 5 crime in EU has the same punishment as a level 3 crime in the USA so the USA is draconian.
The actual real world injustice is if you're innocent and demand your right to trial, we give level 8 punishments for level 5 crimes to encourage guilty pleas and "save money". Because we value saving money over justice and fairness. Or maybe we take a weird statistical approach to injustice; yeah it would suck to do time for a level 5 crime but a level 1 punishment might not be worth the 10% odds of success.
This has a weird and horrible interaction with mandatory minimum sentences. Without mandatory mins, "yeah he probably didn't do it but he's pleading out to a lessor charge" can result in a very fair punishment like mere probation. But with mandatory mins you have to throw the guy in the slammer for decades or let him walk and thats kinda messy. OR being messy, does it encourage higher levels of care and research?
If you commit involuntary manslaughter in Germany, like in a fight in a bar off an army base like a case I know of (I'm not even tangentially involved in other than being in the Army at the same time), yeah, you'll get like 3 years at most. And if you get convicted of manslaughter in the USA you'll get like 8 or so years. That seems terrible.
The difference is you get convicted of manslaughter in the USA by doing actual first degree intentional homicide and its plea'd down to involuntary manslaughter. In Germany the laws are different but vaguely comparable to first degree would get you 15 years minimum, which is actually more draconian than the punishment you'd likely get in the USA due to overcrowding.