Many years of experience in teaching A-level and Higher Grade subjects lead me to believe that both statements are justified. Students are better prepared and they are no better educated than they were 20 years ago.
Today both teachers and students focus their efforts on finding out what sort of hoops examiners prepare for them, so that they will know how to jump through them. They gear themselves to answering the specific type of question set. Ten years ago some of my students attempted the A-level mathematics papers I sat in 1968: they failed them abysmally but they all went on to get top grades in their own exams - where the style of question asked was different though the syllabus was identical.
This process is most clearly visible in the preparation for entry to Oxford and Cambridge colleges. Independent schools and some state schools employ many teacher hours preparing students to jump through Oxbridge hoops. "Success" rates at such schools are notably higher than elsewhere; they know how to work the system. This reflects a high degree of training. It does not necessarily indicate that the student is either better educated or better prepared for university.