system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why are games sold in disks? Wouldn't usb drives be more efficient and save space on the console?
gpt
USB drives are much more expensive. They don't seem like they're that expensive, maybe $10 or so for one with the same storage as a blu-ray. But when you're mass manufacturing, a single blu-ray disc costs pennies to produce. Shipping on USB drives would either increase the price of games or make less profit for the publishers.

Also, as we go into the next generation of consoles, USB drives won't be fast enough. The SSDs that are going to be in next gen consoles wipe the floor with the speeds of a USB drive, so you'd have to install them to the SSD anyway.