[uni] Why is SG’s A levels so much harder than UK’s, but british students’ standards

apologies for the poorly worded title.if u don’t already know, our A levels are pegged at a much higher standard than what the british students do.but it’s not like the british kids lose out to the SG kids at unis such as oxbridge?idk how stupid my qn is but i’m rlly rlly curious on why this is socan any senior at UK unis shed some light about this?