Is there a reason why Lego bricks are not the same dimensions in each direction?

As you know, the 1x1 brick is slightly taller than it is wide/long. I tried investigating the internet but no one has posted a clear answer, just speculation. I know modulex existed and they specifically made it to have the same dimensions in each of the 3 axis, but my question is why was it not like this in the first place? Is there an actual confirmed reason? How did they choose the exact ratio to use and for what purpose?