It's true that SpaceX's previous landings have used legs, but that's either been Falcon boosters (much smaller/lighter than Starship boosters, AKA "Superheavies"), or for Starship's upper-stage (again, much smaller/lighter than Superheavy boosters).

The catching system looks crazy, but it might actually be easier than landing a Superheavy on legs. The ground is a larger target than the catching arms; but its maneuverability and shock-absorption are famously low.