I understand your points. However, there is no doubt that Elting's Swords, and Chandlers Campaigns, are ideal for somebody who just wants a single volume overview which, large though they are, is all they can hope to be bearing in mind the vastness of their respective subjects.
Somebody, I forget who, said that Swords was the product of a good library. The inference of the comment was that Swords was based largely on secondary and published primary material, and did not contain any new research. The same could be said of Chandler
What they both do, however, is to integrate and precis this material into single readable and accessible volumes which, in addition to being good overviews, are also useful, as Mark points out, for the younger reader who interest is just germinating.
'But when I became a man, I put away childish things'.
Like you, I have outgrown books such as Swords and Campaigns though I would want them on my desert island - you could make a pretty good raft out of them.:-)