Yes, countries should change their official currency to the U.S. dollar, because the dollar is strong. Countries who decide to use the dollar are making things much easier for themselves by making sure that they are using a currency that is strong. Additionally, they can save a lot of time and money by just using someone else's currency.
I find the idea of everyone adapting to United States currency completely absurd. As much as some people try to, there is no evidence to say that there's any reason why the rest of the world should cater to our country. Additionally, inflation could become a huge problem in some countries and then we're all at risk when using the same currency system.