Why doesn't it just lift a single extremely large block when electricity surges and then very slowly drops it back down to generate electricity (no need for complex hook-and-release)? The maximum capacity would be determined by the maximum height of the tower along which the block is lifted.

Or why doesn't it just have many medium motors; each permanently attached to a single medium-sized block? Why should the relationships between motors and blocks be one-to-many?

Lots of small concrete blocks, a camera and a hook to latch onto them one at a time sounds overly complicated and error-prone - Not to mention how much precious time would be wasted getting the hook through the holes and then coordinating the lifting so that each block ends up stacked nicely.