How can I display a list of users who have the same taxonomy term
First of all, thank you very much to @leymannx, @GiorgosK and @prkos, because without the three contributions I wouldn't have achieved the desired result.

These are the steps I have followed to display a list of users who have the same taxonomy term in a page with a specific path pattern: people/staff/A/, people/staff/B/...


As @leymannx initially suggested, in my view a wildcard in the path was missing. So, instead of people/staff/, I have changed it to people/staff/%
As @GiorgosK illustrated with his screenshot, I have included a Relationship field_staff_area: Taxonomy term, and then a Contextual filter on Taxonomy term: Name using this relationship.
Finally, as @prkos precisely described, to show the actual term name in the URL I also needed to configure the Contextual as follows:

a. When the filter value is NOT in the URL: Select the option Display all results for the specified field

b. When the filter value IS in the URL or a default is provided: Select the option Specify validation criteria. Then, select Taxonomy term name in the dropdown, and, finally, check the vocabulary we intend to use (Areas in my case).