Because it’s currently an online service that hosts this secure transaction, all the app makes is a call to that service and waits for a reply. I do agree with your logic though, There could be something in place along those lines.
Arguably, A better solution would be to create an elicenser emulator to support legacy users via serial number entry, and hope that the piracy which inhabits their legacy evolves into paying users wanting to update to C12 and beyond. But even that must be a ton of work.
There’s no way they can keep this operational and managed on a user basis without compromises, and even if you had everything they could possible offer you’d be at the mercy of already outdated hardware and O/S. It’s a dead end, basically.
Remember that the dongle supports so many products that are outside of SB too, and the licensing of different tech, content and plugins. Even if it’s financially/technically possible, legalities are the other complication.