What were the exact freedoms your child was missing?
On the general side: I'd say the German approach for kids (2-12) is "super strict on the basics, then have at it." So you are very strict that they must stand behind the yellow line, don't interrupt grown ups, behave yourself at the table, etc, but once you have the core down there are few restrictions (this changes as you grow up...I like to joke that Ordnung is the German state religion). So he was used to unsafe playgrounds, coming home late from just exploring the U-bahn with his friends (all ignoring texts from parents) etc. He compared that to American kids who seemed to always being told not to do things without having a set of basics to make their own decisions. He had one Palo Alto classmate who was grounded if he wasn't home 15 minutes after school let out!
An example: in grade six he and his friends found a bottle of vodka in the schoolyard (urban school). As any 12 year olds would, they took one of their gym sneakers, filled it with vodka, and set it on fire. The maths teacher passed by and said "boys, school starts in a few minutes; don't be late" and kept going. He told me he'd be expelled from his US school if he had matches or a lighter. In Germany that didn't even rate a letter home from the school.
He also complained that grownups were always involved. Schools have police officers in them, scouts have parents involved, etc. Kids don't get to run things and screw them up like they do in Germany. I went to a Christmas service in a church where the kids wrote and put on a Christmas play -- apparently Noah brought the animals, 2x2, to see the newborn. I am not christian but I'm pretty sure that isn't doctrine -- but everyone seemed to like it.
He found the US school routine quite rigid with little time for exploration of the material but instead memorization. If anything the US seemed more like the asian schooling my mother went through, or perhaps the prewar Prussian system. I know the US kindergarteners are told to learn the alphabet while the German one was mainly focused on getting along and learning, by the end of the year, to keep your clothes on all day. They left the alhpabet (in two languages!) to the first grade.
HTH
There were rules on my pre-American childhood. Strict rules - but as you say, there was freedom - I thought nothing of cycling off into the mountains alone in the winter, of getting on a train and going to the city to meet friends, of building a treehouse in the woods complete with punji traps.
Cue America. I spent most of the year I was at school there being suspended for such misdeeds as walking the few miles home instead of waiting for a broken down school bus, climbing trees, and sword fighting with sticks; being a kid, in short. Hell, they even suspended me for reading under the desk, because I usually finished the period assignment in the first 5-10 minutes.
The breaking point was when I cycled from our ‘burb to downtown Chicago to meet a friend for a movie. My parents knew where I was, it was the weekend.
Another parent from the same school spotted me cycling around downtown. Called the police. I got home that evening to find half a dozen cops sat there at the house, threatening my parents with me being put into care, them being imprisoned, and all the rest. Apparently I was in mortal danger by... being on a bicycle without an adult?
After that, they didn’t want me going anywhere without them or another adult. I ended up just not going anywhere.
I went back to school in the UK.
Also, the education was years behind that which I had had previously - I mean, they only had two subjects - “soclish” and “sciath”. “Bored” didn’t even begin to cover it.
In a way, in my case, the strictness at home made the freedom of the streets both more cherished and more meditated. I think this goes to the "basics" from two comments above-- I had the upbringing to make my own decisions and wasn't just told "no" blindly.
And perhaps in that strictness was also the motivation to get out of home and enjoy some freedom? If I were cozy and "free enough" at home, I wonder if I'd wanted to get out so much.
Again, this is a teen ager speaking, so make of that what you will.
I'm all for letting kids be kids, but I do wonder if this is a bit too far in the other direction. Playing with fire can in fact cause buildings to burn down, and, y'know, maybe there's a reason we have fewer of those incidents today than we once did.
But maybe that's my American viewpoint showing...
Kids independence must go hand in hand with knowing when the real harm can happen and responsibility to avoid such situation.