I've always adored the cyberpunk aesthetic of surreptitiously passing SD cards around between people to transfer files, so I love looking at these sneakernet projects.
I just pray that things will never get bad enough that I actually have to use things like this on a day to day basis...
Not just under dictatorship. An attack on networking infra can yield very flakey connections.
Under dictatorships, you will be found guilty if you are found with an SD card full of encrypted files.
While the encryption does protect your data, it definitely doesn't protect you. Probably hurts you, as people will start applying iron bars to find out how to uneceypt your data.