In some countries where English is taught as a foreign language to young learners, the performance of speeches in English is seen as a valuable tool for pronunciation, vocabulary learning and confidence in using the language orally and publically.
While I would not dispute that it is possible for these factors to occur and to occur well, it needs to be pointed out that performing a speech in one's native language is not every kid's idea of fun learning, much less a speech in a foreign language. Some of the most serious problems I have experienced in helping young learner students learn and perform English speeches in the South Korean sphere are generally orientated around the fact that students are not invited/encouraged to have input into the selection and building of a speech themselves - all too often parents and institutions want a story or dialog to be rote-learned to the point that the student is ready to jump off the top floor of the building, and whether or not the student actually understands (much less believes or likes) what they are (so publically) saying is considered to be very much secondary to looking and sounding good in English up on a stage, if it is even considered at all.
English Raven members have access to a supplement here that takes the view that speeches can be good for young learners of English, but that students need to be intrinsically involved in the process from start to finish. The English Raven speech builder workbook first encourages students to brainstorm ideas and topics they would like to base a speech on using their mother language. They then go through the process of writing up their speech, still using the mother language and using assistance from bilingual teachers. When they and teachers are happy with the speech, it is translated into English by the bilingual teacher and then given some touching up by a native English speaker. From there, as students embark on memorizing their speech, the workbook guides them through activities involving intonation and identification/application of sentence stress. The workbook also contains a 'word workbench' - where words the students are having difficulty understanding or saying can be given some individual attention. English speeches need not be a boring, taxing and meaningless enterprize, but rather the center-piece of a range of valuable learning activities involving students' own interests and creativity.