I’m talking about size.

Both countries are absolutely massive, many things will be completely different depending on the area.

They’re kids, let them be kids. I went to a school in the US that had a similar system to that, and, yeah, I did feel a bit academically behind my peers going into SHS, but I grew to appreciate what it gave me later in life. Plus, I still got into a top university (albeit after community college), and I’m happy where I am now, so it’s all ok.