X is a stand-out work of genius, head and shoulders above everything else it was contemporary with, at the time it was made. It was the confluence of strong artistic vision, technical excellence and innovation, and near-flawless execution, where all the parts managed to come together cohesively without any thematic friction - which rarely happens in any project. The reason X is better than 99% of stuff made today is because it was better than 99% of stuff made then, too.
Someone probably will make something as good as X this decade, but expecting most things to be as good as X is absurd. Remember Sturgeon's Law - 90% of everything is crap.