Sam Harris book on lying

Sam Harris book arguing that you should never lie. I'm not pro-lying but overall not very convincing. He has a few various claims

(1) It takes a lot of mental effort to keep track of lies. But if you say the truth it takes no effort. But later he argues for delicate truths and strategic omissions. Which seem possibly harder to manage than lies

(2) If people will realize you're lying but not call you out on it you will damage your relationship without realizing it. For instance, if you lie about why you cancel plans. I think he's on the strongest ground here

(3) You put off a potential truth that could be useful for your friend. For instance, he had a friend who asked if he was fat and Harris told him he was. I think he might be right that the truth tends to be good for your friend. But not clear if its worth the effort. And they might take it the wrong way. So its just a question of cost-benefit analysis