These files are often "exclusive" to a specific release group that has optimized the compression settings for mobile users in specific regions. The Impact on the Film Industry
To put it in perspective, a standard high-definition (720p or 1080p) movie from a service like Netflix or Amazon Prime typically consumes between 1.5 GB to 4 GB of storage per hour. A Blu-ray rip can exceed 20 GB. new movies 300mb exclusive