I went through the completely exam dominated Irish education system, and my DCs were/are in the American system, with the gpa/exam combo determining grades/SAT/ACT/common app/university applications featuring multiple essays, form filling, expectation of being a terrific all rounder and future President, and I know which system I would prefer.
DD3 has just completed her ten university applications, and it has been a rough few months for her, as schoolwork and a heavy homework load proceeded apace alongside hours spent writing and perfecting essays with titles like 'Why?' for the purposes of her university applications. But I would still prefer that to the looming Leaving Cert, a single exam on which rides the rest of your life, at the end of secondary.
A friend of DD2's went abroad for a semester during high school and attended a very expensive (but not selective) girls' school close to my old school, and reported insane levels of stress related to the Leaving Cert.
Stress certainly exists in American high schools. But the choice of good universities is much wider than that in Ireland or even in Britain. If there is something in particular that you want to do, and you are willing to apply to 14 or 16 places, you may get lucky with your biomedical engineering plans. There is a wide band of very decent universities below Ivy League level, where graduates will emerge with a good chance of getting a good job, depending on the major. Finance grads from say the University of Iowa, with appropriate personal qualities can do very well for themselves.
American universities also offer the beautiful concept of liberal arts education, where you do core coursework for two year sand spend two years on your major. You don't have to decide at 17 what you want to do for the rest of your life. DS started out thinking aviation, dumped that owing to cost factors, decided a psychology track would be his best option, and ended up with a degree in Biology and minor in Chemistry. American students for the most part have options, and can find what interests them best while they are in university.
Many American students get extra coaching, tutoring, have parents willing and able to ferry them around their region for travel teams in various sports, or to music or art classes, or to special music camps, or the right summer camp, or to residential sport camps the entire boys' varsity soccer team in my DCs' public high school used to spend summers in the U of Michigan soccer camps from age 10 onwards that cost a lot. However, there are also many students who put in the work and dabble in a sport or two and do some volunteering and still get into great universities.
Many students who are not at hoity toity summer camps are also aware that the band of university they will be applying for is 'very selective' and from an early age. I would suspect that there are very few students who end up being accepted at Ivy League schools whose parents didn't steer them in that direction from an early age. The steering doesn't have to be Amy Chua-style explicit or direct exhortation or pressure. But I know several families who are American of all backgrounds, as well as Irish, Nigerian and Russian immigrant families whose children have known from an early age that in their families, members apply to a certain band of universities, and the sort of time commitment for homework, and the sort of motivation to get the grades necessary are understood. It's just a quiet assumption made by people who know from their own experience of other school systems that their children have what it takes, or in the case of American families, knowing that their children are bright.
I do not consider this a bad thing. There are children in the 'hood who are told in kindergarten that they can be anything they want to be by their teachers. This sort of thing makes me cry, because no, these children will not be what they want to be unless someone takes them firmly in hand and makes them do the necessary work, and it is very likely that they know nobody who understands what sort of work goes into getting a student to the point where they send off an application to Cal Berkeley or even to Eastern Kentucky with any hope of success.
In the last few decades, the prospects for those in the US without a degree have diminished rapidly. People who are now doing ok without degrees are possibly the last generation who will be able to get by without one.