Micro formats like our phones and compacts use have advantages, small so can always be carried, lots of depth of field. Microfourthirds, significant quality improvement, good enough for many applications. DX crop (1.5x) a step up again in quality, better noise and dynamic range. Small format i.e. 35mm full frame, loosing depth of field which can be used creatively, again better noise and dynamic range. The next step up is the cropped medium format, then full frame medium format, cropped large format then full frame large format.
As you see with each increase in format you get better noise, but less depth of field, which can be a positive and a negative, better dynamic range but also the way the image is draw from the lens characteristics differs from format to format.
You cannot state one format is better then another, just different.
Its been interesting seeing the anger on the forums that the new mirrorless Hasselblad and Fuji’s have generated. Users of 35mm full frame, and mainly Sony A7 users have long said that full frame 35mm gives significant advantages over microfourthirds and DX. They have a case for microfourthirds if your willing to put up with the size and weight good quality full frame (35mm) glass is and the issues that brings, less so with DX. But now their claiming there is no advantage to cropped medium format over full frame 35mm, basically using the same arguments the smaller formats have been using against them. They cannot have it both ways.
Each format has its advantages and for many people having a foot in two systems can be useful. Microfourthirds and full frame make good partners, and DX and cropped medium format also make a good pair. You can see why Fuji have gone for DX with their X system cameras and now medium format with their new medium format camera, lets home they make a success of it.