You are right. That wouldn't require a Blu-ray. The ISO expands quite a bit after it is installed to your SSD. Maybe they are backing up their whole systems

You are right. That wouldn't require a Blu-ray. The ISO expands quite a bit after it is installed to your SSD. Maybe they are backing up their whole systems to the Blu-rays? Or have big movie collections which some comments indicated was expected. I've used USB for a while, don't think I've even used a DVD to install Windows. Did use them to back up years ago, but now a HDD for that.