I have been lifting for 6 years (non professionally) yet never seriously tried the Deadlift exercise.
Is this exercise necessary for intermediate\advanced bodybuilders in any way?
The deadlift is awesome
I find deadlifts very productive. Since they're a multi-joint, multi-muscle exercise, they promote growth across the entire back and legs. Done heavy, I've found them very efficient at adding muscle. This is partially because I am a novice. It might be different for your situation.
I don't know of many exercises that could be said to fully replace the deadlift. Squats? Romanian deadlifts? Barbell hip thrusts? They're all close, but not quite it.
You should deadlift
Since the deadlift is easy to learn, safe if done correctly, and simple to do heavy, I think you would love deadlifting. Start light and add weight frequently.
The Deadlift works nearly every muscle in the body.
VERY IMPORTANT: You must use proper form. Most important is to Hold a Deep Breath, Contract the Abs, and arch the back, to help prevent a herniated disk and Sciatica.
You can lift heaver loads if you use a Reverse Grip vs. the Classic Grip.
The Deadlift along with Squats and Bench Press make up all the exercises in Competitive Power Lifting.
The Deadlift should be the first exercise in your workout routine.
Putting the Deadlift in your workout routine should be done with care.
For example, combining The Deadlift with Squats in a same day workout if you are not a competitive Powerlifter, will very likely over train your Quads and Gluteus Maximus.
These are the muscles that are worked hardest by the Deadlift:
Quadriceps, Biceps Femoris, Long Head
Trapezius, Anterior Head
The Deadlift also puts a significant load on these muscles.
Flexor Digitorum Profundus
The Deadlift is the only common exercise that works some specific muscles.
The above image is from the first edition of Strength Training Anatomy, Copyright 2001 by Editions Vigot, Paris France.
Absolutely not necessary, deadlifts are great but still overrated. You can replace the deadlift with other exercises if you want to.
You should give it a serious try though.
If you're lifting but not doing deadlifts then you're not actually lifting. I say this with tongue-in-cheek but a serious tone.
The same goes for squatting.
Generally, your deadlift will be the movement for which you can move the most weight and the effect of moving this weight on your body cannot be overstated.
You're not just hitting muscles but adrenals and CNS. You're building the core of your body like nothing else, which makes you strong in all sorts of other movements.
Just standing there and holding the weight will isometrically load you up like nothing else.
Proper form requires good back and hamstring flexibility, which is something a lot of lifters don't have. Strength without flexibility is a recipe for injuries.
So while the deadlift looks just like you're picking something off the ground (which is true), there's a lot more to it (though not as much as in a squat). And like the squat, this exercise pays huge dividends.
They are not necessary but you miss out on a lot by not doing them. The benefits far outweight the cons. See more here: http://www.bodybuilding.com/fun/drobson101.htm