You can train hard or you can train long. You can't do both.
Most people think they are training to failure but aren't training anywhere close to failure.
I did DC training my first couple of years training. In DC training, you do as many warm up sets as needed and then do 1 all out work set. Knowing in the back of your head that you only have one set to stimulate the muscle, it really teaches you how to train hard and leave nothing in the tank.
That is not a good idea. Ocassionally on some exercises, especially on the last set it is a good idea, but if you will go up to failure with each attempt, you will not be able to perform properly all of the sets, and there will be an increased risk of injury. So do that only on one-two sets.