If blood transfusions are dangerous why are they still being implemented?

There are a lot of medical papers written by several doctors stating that blood transfusions are not safe after all like many people think. Apart from the risk of bacterial and viral transmission they also state that blood transfusions can cause lung and kidney failure. If that is the case why are they still playing them of as safe when they are not? What will happen to the people who have recieved transfusions does that mean later on in life they could suffer kidney damage or failure? Or any other serious complication or organ failure years down the line?