I think lots of people have atcually forgotten how hard it is/can be to get AAA. Many people who haven't actually started A levels or have just started are being a bit cocky. So many people go in thinking they will get AAA easily, it's funny. I also believe the reason so many Med students do get AAA is because they work so so hard to get AAB, because they're so scared of missing the grades.
I don't know whether exams have got easier or not, but it doesn't matter because everything is in competetion to everyone else.