Calligra doesn't show word count dynamically, that is, it doesn't display the amount of selected words.
It could be shown in the status bar or on the statistics docker.

This is a critical feature for translators, editors and proofreaders, e.g. word counting is the first step for stipulating the price for a document and its respective service, and the correct size for certain document elements.

The total number of words in a document is not sufficient for various use-cases in those fields. For instance, in my use-case, since I work with academic articles, I need to be able to easily count words in the abstract, and since references aren't always revised, in such cases I need to select all pertinent text before the references in order to properly count the total amount of words according to the service I provide, possibly even including parts of the text that come after the references as well.