"But anyone is going to stomp when fed, doesn't mean they are OP"
I hear this all the time when talking about OP champs. The problem is that they get fed BECAUSE they are OP.
Also, the fact that there are champions that literally snowball off of one kill is so stupidly broken, it can't be put into words. Someone could have gotten that first kill due to pure luck, and they become an instant monster you can't deal with for the next 30 minutes.
This is what people need to understand, so the game can actually move towards being balanced.