On what factors does the necessity of including a cover letter heavily depend?

Answer

The specific role, the industry, and the person receiving the application

The decision to invest time in a cover letter exists in a grey area, determined largely by the requirements of the specific role being targeted, the industry context, and the preferences of the individual reviewing the application.

On what factors does the necessity of including a cover letter heavily depend?
jobapplicationrequirementresumecover letter