Coming from Canada, I am so surprised at the amount of standardized tests and the level of competitiveness at US schools, for all levels of post-secondary! When I was in school, I only took 3 standardized tests ever: Grade 4, Grade 7 and Grade 10. These are low pressure tests just to evaluate how students are doing. They aren't used to compare schools against each other and assign funding, so there's no pressure from the school to get their students to do well. I was so surprised to learn that the GRE even existed. I didn't take SATs at all and Canadian schools in physics/astro do not require these tests at any level.
In Canada, getting into grad school is also more like a job interview and hiring process, like in Europe. This was not a big deal for me though, since I did a co-op work program in undergrad, so I had interviewed for research positions many times before. As Canada is really big, you often have Skype interviews rather than in-person interviews, but many schools will still fly you out to meet the faculty. One big difference with the interview process is that you do need to decide on project(s)/advisor(s) ahead of time and that you might be the 10th overall ranked applicant and still get accepted over the 5th overall ranked applicant because maybe all #1 through #5 wants to work with another professor. That is, you are only competing against other students applying to work in the same group(s), not everyone in the department! Personally, I like this method better because it's more like the world I'm used to (i.e. applying for jobs is the same way). However, now that I am in the US, I do see an advantage to the US system where you don't have to commit before coming to grad school. But, maybe requiring students to make a decision earlier isn't necessarily a bad thing (Note: Also, PhD programs come after Masters and the Masters acceptance process is more similar to the US where you don't have to choose right away).
Also, the other really interesting thing I learned about US colleges is how many essays and even reference letters(!!) that high school students had to submit to apply to University. In Canada, for Universities (4-year degrees) I just submitted my high school transcript in February and if it was above some number, then you get early acceptance, otherwise, you resubmit your final transcript in June and if you're in the top 2000 (or however many spots they have) then you get in. It's weird to me that US colleges want to see things like leadership or volunteering etc. to just get into a bachelor's program. The college (2-year degrees, with transfer options to 4year universities, also called community colleges in the US) are first-come, first served. The first X number of applicants that meet the minimum requirements are accepted. The idea is that the government funds enough colleges that everyone who wants to go is able to access higher education. So typically, a Canadian high school student will apply for a college early on (fall of Grade 12) to have a backup plan, usually a college in their hometown, and then apply to 2 or 3 universities.