From my general experience, the majority of people I have met have told at least one lie (by admittance or direct observance) and their parents had also told them to never lie in the past.
Similarly, I am sure this also holds true for the population of this and other sites, and most of the people here would have told at least one lie despite being told to never lie.
Since children almost always grow up to tell lies despite being taught to never lie, is there any benefit to this approach over teaching them how to choose when to and when not to lie by weighing the respective benefits and drawbacks? It seems from a naïve perspective that this would better prepare them for a world when lying is extremely common and sometimes even arguably necessary for certain jobs.