Readable is a matter of education. As a C++ programmer I've learned what {} means, and so that is more readable than begin/end which happens to not be the block symbol in any language I know well. Considering all the languages I know I've concluded that block symbols are important enough to be worth learning as a separate symbol (Looking at python where it is white space). Of course I can learn begin/end, but it isn't worth typing those extra letters of the word when something that common can be done in one.

Note too that {} graphically indicate the open/close in a way that begin/end is another reason not to like begin/end.