It's also the main storage on the Wii, DSi, 3DS, (maybe Wii U, but it also had USB storage. I guess the Wii did too.) and Switch. An SD card reader lets you back up your game saves or install homebrew.

More recently there's the PinePhone as well. It's not just expandable storage, you can boot off the SD and have all your OS and files there.

I would say I definitely use SD cards more than flash drives now.

> random SD cards I find laying around

Can we explore that a bit? Laying around your house? Or like on the ground at work?

I seem to remember some corporate espionage that relied on people looking at random SD cards they found on the ground...

Mostly my and my friends' homes, but I do remember finding an SD card on the ground once... Do you think I'm being targeted by spies? :) It had someone's pictures on it, but no identifying information, so I had no way of returning it.

Thankfully random SD cards should be much safer than random USB devices, but it's probably better to be careful.

> It had someone's pictures on it, but no identifying information, so I had no way of returning it.

You could hav put your laptop on a network with heaps of monitoring going on, and then mailed it back to NSA/GRU/MSS/Mossad as required based on the ip addresses your machine started connecting to...

;-)