The wheel still uses energy from the water source to lift the craft. The real advantage is it takes far less water while looking cool. It’s also tall for a lock.

I think the most efficient system to build and use would be a "bucket" and pulley’s attacked to a counter weight. Granted it would have far less summitry and not look as cool. The main advantage to locks is they scale really well but they use more water.

PS: I can't help but wonder how they counterbalance the buoyancy when one end dips into the water. Those curved tips might help and I can world out the geometry in my head but I think they just brute force it.