The UK based O/A system, which is used in many of the former colonies, is not as easy as the North American high school system. O levels is easy. But A levels content is almost as difficult as a typical first year university course.

Yet, students from those systems also face an equivalent huge shock when they switch to university. The reason is fundamentally different. In school, students are infantalized and their own education is not considered their responsibility. In university, nobody used to care whether you sank or swam. So students struggled. But that has changed quite a lot now. Many universities have almost a "no child left behind" policy - yes they do think child not adult who chose to attend university.

So even if students in the past used to attend office hours (I don't know), today they don't because it is no longer their responsibility to learn.