Why does monarchy even exist in the 21st century?

I live in the UK and take no notice of the royals, they hold no interest for me and its just tradition that they are still around. What would happen to them if there were no royal family, where would they go ? The Queen is as far as I am concerned the last real royal, the rest are just a bunch of unfaithful, disloyal, cheating and selfish people, and these are the ones that "rule" over us all. Yeah right, I dont think so...