This emulator only matters for the old MT2/3 cards because those are more common with a credit card than an IC card, because you can write on them to save the profile, instead of saving on the Banapassport server and the card being pretty much a read-only contact card that contains a special string that is a physical password to retrieve your profile in the game.
YaCardEmu doesn't do anything before you connect to the Banapassport service, it's just the card reader. You need to connect to an online server to do anything.
Same analogy happens on real cabs, if you have a reader, but the internet is broken, no saving for you today.