I agree that dividing the largerFunction into smaller ones has a non-negligible cost, and that cost is never mentioned at school. However, I still think that th

I agree that dividing the largerFunction into smaller ones has a non-negligible cost, and that cost is never mentioned at school. However, I still think that the benefits provided by moving them out outweigh it. One think that I found beneficial is that by dividing the big functions into smaller ones, the resulting functions have the same abstraction level. To give an exaggerated example: I try to split my functions so that I never deal with Countries, Provinces, Cities, Buildings, People, Body Members, Organs & Cells in the same scope. I try to only deal with one of them per function (sometimes two, in parent-child cases). I find that 1-abstraction-level functions are easier to understand, and I gladly "pay the price" of having extra one-use names around for this reason. I do try to restrict the scope of those "extra functions" as much as I can, put related functions together, and reduce side-effects as much as I humanly can.