The Count Field is unable to Count the collaborator field. To return a count (length) of users from the Collaborator field, Base administrators are forced to employ a Formula that is not ideal.
How does is solve the user problems?
A base administrator can add a count field to count their users within a Collaboration field without having to Google Search why it's not possible, only to find a formula hack is needed.
Who is the target audience?
Everyone who expects the Count Field to be useful with counting various other elements that are found within the many other Airtable Field types - such as, but not limited to, the User collaboration field.