It’s not just that ,, I don’t know what fuel this SpaceX rocket uses but it’s likely much more energy dense than the Saturn ,, Von Braun used cheap available fuels , alcohol and lox (V2),, kerosene and lox (Saturn)
This is not actually the first such landing test - it's only the first test with the flight-design landing legs. They did pathfinding work starting in September 2012 with a vehicle they dubbed "Grasshopper."
SpaceX Advanced Testing Playlist
The multi-angle 24-story hover test one is pretty cool.