The joy of large megapixels is the ability to crop, select different aspect ratios without loosing too many megapixels, but you will always loose some.
Panasonic took a different route.
- 4:3
- 3:2
- 16:9
- 1:1
You can with most cameras select an aspect ratio but it just crops in camera and you lose pixels. Panasonic created a sensor that keeps the diagonal pixel count the same, so if you switch to a narrower and taller aspect while a traditional camera just looses pixels of the side the Panasonic extends the height.
It’s one reason why a lot of people like the Panasonic GH and compact range.