I wish I was as smart as you. Few words to get your point across.It is for our sake and an expression of Allah's mercy. The judge knows the outcome but the defendant deserves justification. It would not be fair for someone to be teleported to hell without being told why. That is why angels record our deeds and why we have a day of judgement.
"ALLAH IS THE MOST MERCIFUL" one of Allahs attributes is to be merciful.