I'm surprised there aren't adapters to connect two or more micro SD cards to one device and duplicate written data to both of them. I assume you couldn't do it

I'm surprised there aren't adapters to connect two or more micro SD cards to one device and duplicate written data to both of them. I assume you couldn't do it with wiring alone, and would need a chip in there. Even finding a microSD extension was tricky when I wanted to mess about with the hardware.