J, 18 bytes

,"1/^:(]{:)~@,.@i.

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Iterative solution, no built-in cartesian product. This is what peak J looks like.

                       input                                    2
                i.     range                                 0, 1
             ,.@       reshape each element
                       into a one-dimensional array        [0],[1]   (A)
    ^:(]{:)            (input−1) times...             (1 iteration)
,"1/       ~@             prepend each 1d array in A                    |
                          to every 1d array from the previous iteration,|  
                          assembling the results for each A[n] into     |!CANTEXPLAINTHIS!
                          a larger array                                |
                                                         [ [0,0],       |
                                                           [0,1] ],     |
                                                         [ [1,0],       |
                                                           [1,1] ],     |