The magnetic stripe is just data. NFC is a handshake: the chip is a tiny MCU. There is still a root of trust required to prevent MITM, but the device would need

The magnetic stripe is just data. NFC is a handshake: the chip is a tiny MCU. There is still a root of trust required to prevent MITM, but the device would need to be compromised. This is why keys and certificate chains are stored in secure memory that is resistent to side channel, and even physical attack (it breaks easily and the die can't be shaved down).