What is the point of having field IsVisibleInApp on Knowledge__kav if it is always defaulted to true?

What is the point of having field IsVisibleInApp on Knowledge__kav if it is always defaulted to true?

Per documentation,

https://developer.salesforce.com/docs/atlas.en-us.knowledge_dev.meta/knowledge_dev/sforce_api_objects_knowledge__kav.htm

IsVisibleInApp  Type : booleanProperties: Defaulted on create, Filter, Group, SortDescription: Required. Indicates whether the article is visible in the Articles tab (true) or not (false).

Looks like this field is not available for editing, which means it is readonly and it is always defaulted to true, every article is visible in the Articles tab.

Then what is the point of having a field which always returns true?

If we try to create a record with this field value set to false, we will receive an error saying "Field is not writeable: Knowledge__kav.IsVisibleInApp"