Quick take
Midjourney is useful when the job is visual direction, not exact production layout. Use it for moodboards, ad concepts, thumbnails, hero image directions, packaging explorations, and style studies. It works best when you control the subject, aspect ratio, references, and review criteria before generating.
Best fit
Use Midjourney when you need strong image options quickly and can still edit, select, and approve the final asset outside Midjourney.