My understanding is that LCD’s now use LED as a lighting source. As such, it’s not LCD VS LED. Old LCD tech has a different lighting source that won’t last as long as the new LCD’s that use LED lighting. Also uses less power. I also believe the LED lighting tech allows for thinner devices.
Just saw an “LED LCD” at Sam’s amazingly thin and bright. A flourescent backlight LCD looks fat and obsolete by comparison and uses quite a bit more energy.