Mainland Chinese born in the 80's were attending universities in early 2000's.
The percentage of high school students that could attend university was relatively low by that time.
So, the average standard of Ugrad for that generation is pretty high.
Now, 1 in 3 high school students in HK can attend university (locally or aboard).
The average standard of HK Ugrad is not competitive with respect to the post-80 generation in
mainland.
See the English communication skills of local students vs a mainland student in CUHK