Why is the class that has the safely playstyle also the class that deals most damage

ADC's are laughably broken and this has gone on far too long. We have been going months now playing with champions and items that BREAK the game. The enemy team can have 4 adcs on it and 1 support and they can still win the game EARLY. is laughable. Adcs should be afraid to attack an enemy with it instead they laugh at the fact that you just wasted 2900 gold. doesnt matter either. Lets just take 20% of that 200% damage that should of dealt 100% and make it 180%. OH WELL. WHEN ARE YOU GOING TO REALIZE THAT CRIT IS A BROKEN STAT. Im going to laugh so hard when these new runes come out and adcs are killing people in 3-5 auto attacks in under a second with the new keystone.