Medium format offers a 400% larger view over 35mm (based on 6x7 negs/trannies). It is a huge view. 5x4 is even bigger. 8x10 much bigger still. Lay out a 35mm neg frame next to a MF or LF sheet.
Viewing is much easier too. A 3 to 4x loupé is the only thing required to judge sharpness and focus while a loupé up to 10 or 12x is needed for 35mm. Of course, there is a lot more room to consider composition and visual aesthetics in larger formats over the small and undeniably restrictive frame. But never think that 35mm doesn't have its strengths — like loading a film is a simple affair compared to the fumblefest of MF, LF!
For many years I printed Ilfochrome Classic prints from 35mm Velvia. Nothing, including larger formats on lesser media, has ever come close to these. Exposure is much easier in medium format, but much, much more precise manually (spot~) metered. Most people agree that MF and LF are formats for technical expression and mastery of the subject (especially large format). Where 35mm excels is in the speed and spontaneity of everyday life. It's ready the moment you pick it up: LF is not. Even MF cameras, with their often inherent lack of automation, require a structured approach to use, especially since there are typically 10 or 12 frames that could easily be laid to waste by bad decisions.
At the end of the day, however, it is the power of the photographer's subject, composition, technical mastery of, and knowledge of his equipment, and execution of the final print that determines what format is best for his or her needs. Not what others postulate that what works for them will work for others. It doesn't work that way.