"You think you're buying like a Kingston or a SanDisk but you're actually not, and they're extremely poor quality, they're slow, they sometimes just stop working, and it gives people huge number of issues, apps crashing all the time, users losing data, a lot of basically complaints and customer frustration. It's gonna be a while before you finally accept that maybe the reason why it's not performing is because you put in an SD card, right? You're gonna blame the phone, you're gonna blame the manufacturer, you're gonna shout and scream and try to get it fixed, so many different ways until you say, 'Actually, let me just take the SD card out and see what happens.'"
Barra probably would have given the same reasoning if he was still the VP of Google's Android division. Despite many techies' desire to have storage expansion option, all Google Nexus devices bar the
Nexus One lack microSD expansion, and Matias Duarte, VP of design, once
explained that this is because "in reality it's just confusing for users." Google engineer Dan Morrill also voiced a
similar concern on Reddit a while back.
"It is a trend: SD cards will disappear," Barra added. "You should basically not expect SD card slots in any of our flagships."
Here's Why the Xiaomi Mi 4i Does Not Have a MicroSD Card Slot | NDTV Gadgets
it allows the device to use ext file systems instead of a mix of ext and FAT. This is faster and safer -- both for the data on the device and the way it's handled, and access to our own personal data. A journalized file system means fewer file errors, and ext preserves file system permissions so random code can't find your pictures or documents folder.