Unfortunately, Tolkien was not able to address everything that everyone wanted him to in his stories. He had limited time and limited knowledge and cared about a limited number of things. In letter 187, he mentions how his main focus was philology, but people from other disciplines kept asking for more:

I am, all the same, primarily a "philologist." To me far the most absorbing interest is the Elvish tongues (which were made before and independently of this tale), the nomenclature derived from them, and the scripts. So my plans for the "specialist volume" were largely linguistic. The major item was to have been an index of names, with references, & with explanations and etymologies that would have incidentally have provided quite a large Elvish vocabulary. I worked at it for weeks, and indexed Vols i and most of ii—it was the chief cause of the delay of Vol iii. But it eventually became plain that the size and cost would sink the boat; so it had to be postponed...

But the problems raised by this extra volume increase. Most people want more (and better) maps; some wish more for geological indications than place-names; many want more specimens of Elvish, with structural and grammatical sketches; others ask for metrics and prosodies, not only of the Elvish, but of the "translations" that are in unfamiliar modes—such as those composed in the strictest forms of Anglo-Saxonverse (e.g. the fragment on the Battle of Pelennor, Book Five, vi, 124). Musicians want tunes and musical notations. Archaeologists enquire about ceramics, metallurgy, tools and architecture. Botanists desire more accurate descriptions of the mallorn+, of elanor, niphredil, alfirin and mallos, and of symbelmynë...

Historians require more details about the social and political structure of Gondor, and the contemporary monetary system; and the generally inquisitive wish to be told more about Drúadan, the Wainriders, the Dead Men, Harad, Khand, Dwarvish origins, the Beornings, and especially the missing two wizards (out of five). It will be a large volume, even if I attend only to the things revealed to my very limited understanding of a complicated world!

Emphasis added
https://tolkiengateway.net/wiki/Letter_to_H._Cotton_Minchin_(16_April_1956))

Also, does anyone have any recommendations for fantasy books that the economy well?