While this seems lightly ill conceived, it actually makes sense. Super Heavy is going to be very large, as these things go.
70m tall, 9m wide, and while not very dense, still quite heavy.
Not very easy to move around. The plan is to land close by to make moving it back to the launch pad easier.
Original plan was notionally to land back on the launch pad. That is implying a level of accuracy in landing that is really quite astounding. (Consider that while SpaceX has landed 55 stages either on a fairly small barge or a small landing pad, the variation in position is still on the order of 10 feet (3 meters) or more away from the center of the X. Hitting a landing pad exactly without breaking anything seems like maybe that was a reach too far).
They have a serious goal of reflying the first stage on a daily or greater frequency. The farther away it lands, the longer it takes to get ready to fly again. Thus the original plan. If you land back on the pad, much quicker to gas and go for next launch. (Personally I always thought that was overly optimistic, but one can dream!)