There are professional indexers for a reason. This isn’t a slight against Word whose features are mostly adequate, but rather a testament to a conceptually difficult process that needs human judgement. Unfortunately, creating an index in Microsoft Word can be difficult and time-consuming to do on a large scale.
Indexes still have a place, especially in printed books. Online documents (in Word format, web pages or PDF) can be easily searched using Ctrl + F, making an index less needed. These days, indexes aren’t as common as they once were.
