Why multidimensional array element access using indirection operator?

The number of dimensions is immaterial. All arrays are implemented as a one dimensional array. A multidimensional array is simply an array where every element is itself an array.

The only thing actually known about any array is that its name is a reference to the start address. Unlike an ordinary (non-array) variable, the elements in the array do not have names, we can only refer to them by their memory offsets from the start of the array. As such, in order to obtain the values stored at those offsets, we must dereference them. While the subscript operator gives us notational convenience, it's easy to forget that there's actually pointer arithmetic and dereferencing going on behind the scenes.