Ampersands are great because they add subtle visual interest. They are particularly good, imo, for cases where you want to tie a thing together a little tighter. e.g. "Center for Intelligence & Foreign Affairs" more clearly conveys that it's one agency with two roles whereas "Center for Intelligence and Foreign Affairs" is slightly more ambiguous between one agency with two roles versus two agencies ("Center for Intelligence" and also "Foreign Affairs")

The use of ampersands in this Trump post is very odd, though. Very strange.