Easy to say this when you don't have 1 billion people also gunning for the opportunities you want (maybe less since they're in Hong Kong and not the mainland)
From the Wikipedia page for the examination required to get into Universities in HK, the number of test takers in 2020 is:
52,687 [0].
This doesn’t include students using international exams to get in, but that seems to be a fraction of this number.
Still very challenging but not 1 billion challenging.
[0]: https://en.m.wikipedia.org/wiki/Hong_Kong_Diploma_of_Seconda...
There are 14 universities in Hong Kong of which 4 are well ranked. I would say the chances of getting into a decent university for HKers is actually much easier than for Mainland Chinese students.
There are some traditional families who feel the need to do a lot of extra curricular activities and tuition just so that there kid can go into the three prestigious subjects of law, medicine and finance but that's not all families.