Captions tell the history of an aircraft - if you are going to have a picture of an aircraft then you need to tell its story and background - this is only common sense if not for readability then for accuracy in reference. If you were to google F-16 this article is one of the first to be found so this make accuracy and completeness essential in these article (and it does not add too much more in size).  If wikipedia was a dictionary then a simple caption would be ok but tbut wikipedia is more then it is becoming a valuable reference tool as such accuracy and details is essential