So I've spent some time actually doing education here in the US. At one time or another I've taught students from college level down to kindergartners, the bulk of my time so far has been spent teaching university students about science. You asked for flaws so I'll give you those.
- Kids aren't taught nearly enough outside, or how to do stuff. In the US our students in 2017 mostly lack exposure to the physical world. By the time they are in college most of them think what they learn is utterly disconnected from the world around them, and that my job as a professor is to give them a bunch of shit to memorize and a multiple choice test to put those items on and forget about so they can memorize the next thing. We start this early. When my job was to teach Biology it was tough. Most 20 somethings had never cooked a meal, or flipped over a rotting log, dug in the dirt. It's tough to explain what osmosis is going to mean for a cell to someone who has never brewed tea, or competition/interaction to someone who sees the world in two kinds of tree, four kinds of bird, five kinds of bug and one kind of grass.
- Religion isn't helping. It could, but it isn't. When I taught little kids in Ohio I had to pussyfoot around evolution. Not because of the kids, they got it intuitively. When you've dragged them out of the classroom and you're sitting in the woods with them talking about animal and plants fighting it out for life again and again, the kids they get evolution. Even co-evolution and invasive species (my part of Ohio just lost all it's ash trees). These things are intuitive to fifth and sixth graders in the right setting. The trouble is the parents. In my part of the country you have to choose your words carefully before late high school, and in truth, it's the perception that a parent could cost you your job for telling their kid the truth using the terms we would use as scientists. This makes it harder to get rid of misconceptions, because even when a kid understands some loaded topic, like say evolution, or some historical example of appeals to racism or abuse of patriotism, we as teachers have to discourage the kid from making the connection to the world around them. Which is kind of the point... so yeah. Which brings us to
- Parents. This is a problem up until around the middle of highschool. The first part is the most intuitive part, parents directly interfering with their kid getting taught something useful, or coming in to try and get you to give the kid a grade they don't deserve (this happens up until... usually it is young kids but not always, some will do this until they graduate from college). MOST teachers want to do good, but a lot of us are restricted to certain forms of teaching (late high school to college) somewhat by logistics, but mostly by fear of parents (K-12). Teachers don't usually get backup from their administrators, most of those act as surrogates or advocates for parents. If you ever wondered why when you're 10 years old sitting in nice neat rows with clean shoes and bored out of your skull while someone drones on and on about what the inside of a frog looks like, it is because if we took you out to the creek and showed you some real examples 10 parents would be calling in about muddy shoes and pants, 5 outside the teacher's door about skinned knees, and 1 outside the principles office irate that when Johnny caught a snake his teacher told him about it's habitat and what it ate and not that it was the spawn of satan and deciever of Eve. These are the direct influences. The indirect ones are even more problematic. Parents don't teach their kids stuff. For better or worse the bulk of the US is two income households. This means all sorts of good things for female empowerment. But kids aren't really raised so much as shuffled from caregiver to caregiver. I don't know how to fix it, pay people like they are single breadwinner households or something. But as a teacher it makes it super hard, when most kids aren't interacting much with their parents. They aren't learning honesty, or empathy, or the value of hard work, or even that adults are people, or how to handle stuff at home. So... I don't know it's kind of intangible, but they just don't really get life skills, so when you're asking them to figure something out and they struggle, a lot of kids just fold up. You can take five to ten minutes to get the kid on track, but there's a cost to that. It's five to ten minutes the rest of the class is waiting on you. It is pretty frequent, and uniform across age class, and I see a lot of teachers struggle with it.
Effort/reward. So it's still pretty intact through the lower grades (except in charter schools) but teaching in the US is still a pretty stable profession. EXCEPT for colleges. So I guess it started in the 70's but really took off in the 90's But the old tenure system has pretty much been scrapped. There are still tenure folks alive and in jobs, but when they retire they aren't getting replaced. If this was being replaced by real jobs with health insurance, and stability that would be fine. But... well we made too many phds. So yeah adjuncting is a thing. It's worth looking up what that is, but suffice to say that when I was a college prof I teaching at three different schools and was making less than full time at McDonalds. Every semester it was pretty much a crapshoot if any university or college would have work for me or not, or what I would be teaching until about a week before (on several occasions after) classes started. This will eventually break higher ed in the states. It's cheaper than the old system so the schools survive a lack of state funding like the old days. But I saw a LOT of good teachers get ground into dust. There is still the tenure system for researcher, but that is based on how much grant money they bring in for their research almost never or minimally on how well they teach.
Money. It screws things up, badly. At college the dynamic was depressing. Students could be sorted into roughly four categories. Some didn't get what school was for, and thought it was for socializing. They learn nothing. There are others who put in a middle amount of effort, and get a middle return. Then there are those who are really there to learn. This group has a subdivision. Those whose mommy and daddy are paying for school (fair number of those in the first group also), they get a huge amount out of it, and usually get flawless grades. And those that are working their way through. They know there's a lot there to gain, and they want it. But they are just overtaxed. On paper you can't tell the difference between them at the group who middle through with basic effort, but in class and in discussion, it shines through are really giving it their all. This effort isn't reflected in their grades, they are just overtaxed by life. There are exceptions, but not many. At the k-12 level money doesn't make a difference within a school, but instead between them. For whatever reason we thought it was a good idea that a school's budget (beyond keeping the heater running) should be based largely on LOCAL taxes. So rich schools have more money than they know what to do with, and poor schools, well they have heat. We'll never get rid of this because, you just try telling some rich suburban mom that her tax money that used to go to her little Timmy's school is now going to have a portion go to some poor kid because it would be better for us as a society if they had an even shot at life.
Those are pretty much the flaws I've come across in the US education. The standards aren't bad, but the pressure is, and now that they are taking are adaptive tests, the time spent on standardized testing is dropping dramatically. Essentially we are locking our teachers into a certain style of teaching we know isn't the best, and we have risk/reward out of wack.