I don't believe that standards have fallen, we just have far better facilities nowadays.
I come from a working class background and I would naturally struggle to afford books. The internet offers me an amazing wealth of information from which I can revise, which has helped me to get my grades.
Added to this, we know have far better resources in the form of revision guides etc.
Saying that A levels are easier now is like saying that a minute is a shorter period of time because athletes are speeding up. Our tests aren't getting easier. We're getting better guidance for them.
If we did things by percentages, then it would be better for determining the best applicants. Very few people get 5 100% scores, so it would help pick apart the applicants for university, even at the top level.