Do the pins pogo? If not, there could be difficulties maintaining contact, and could be a reason it doesn't work. The other reason, obviously, is the EEPROM in the cartridge has a different interface. And, of course, it could simply be defective or ESD damaged.
As for the chip, of course it's a dirt cheap microcontroller of some variety with a bitbang GPIO interface and 100 bytes of code. It's the only design that makes sense here. As long as it's compatible with the cartridge interface and the pins can reliably maintain contact it's super simple to make this work. A first-year EE student could put one together as a school project without difficulty.
I actually find it kind of rude to insinuate Chinese engineers can't design an EEPROM wiper. Get real.