High level (maybe even philosophical) points about hand sewing
Hand sewing can be stronger than machine sewing. [1][2]
At least, on an individual stitch basis, hand sewing is stronger. However, machine sewing is much more consistent with both positioning and tension, and it can place more stitches in the same amount of time. Therefore, if you have many stitches to make, then in practice the machine stitching will almost always be stronger.