Except Vipershark specifically asked for it.
Also, the way you asked it is not just impossible (due to movement not being restricted to solid blocks) but also too CPU extensive, seeing as it needs to recalculate and update the distance traveled at all times.
And it really is practical. What if you wanted to have a hole of exactly 108 blocks wide. Normally you would have just counted all 108 blocks. With this, all you have to do is set a starting point for your hole, perhaps even dig yourself in, then walk so manyth blocks in one direction and see how the x, y and z value change without having to bother to count.
Also, the way you asked it is not just impossible (due to movement not being restricted to solid blocks) but also too CPU extensive, seeing as it needs to recalculate and update the distance traveled at all times.
And it really is practical. What if you wanted to have a hole of exactly 108 blocks wide. Normally you would have just counted all 108 blocks. With this, all you have to do is set a starting point for your hole, perhaps even dig yourself in, then walk so manyth blocks in one direction and see how the x, y and z value change without having to bother to count.