But they're not cartridges, regardless of how people refer to them. To be a cartridge, as traditionally applied to video games, the ROM must be directly accessible from CPU space (whether completely, or through banking).
They might be designed in the spirit of cartridges, but they load files into RAM from a filesystem, and never access them directly from the storage media. Thus they're fancy SD cards that really, really want to be carts, but aren't.
Cartridges died with the GBA. Unless you count the myriad unlicensed, bootleg, or knockoff consoles that exist with multigame carts.
Edit (30 minutes later): The inherent nature of cartridges also allows direct access to peripheral chips (coprocessors, etc) found in the cartridge in CPU space as well.