Make sure to load RAW files in an app that can definitely read RAW, such as Darkroom.
Unfortunately, when an app doesn't understand how to read a RAW file, the system will instead display a low-resolution thumbnail image. While a RAW file is around 12 megapixels, these thumbnails are around half of one megapixel.
Even Apple's built-in Photos app can't read RAW files. Compare the these two photos:
These are both the same file. The blurry image on the left was loaded in an app that can't read RAW, while the one on the right was loaded in an app that can.