Yes honesty is part of truthfulness. Maybe so many people are dishonest because there's less understanding of Kamma and responsibility. Many people have the belief that what they do, say and think won't have a result. And that they can do, say or think anything they like and not reap any unbeneficial results. So perhaps they feel that truthfulness is not necessary. And lying may help them to get out of a particular situation at that moment, but they may not understand that although they avoid the Dukkha at that time, they might get into more Dukkha later. And normally the Dukkha only gets worse and worse and becomes more and more difficult to get out of.