The form factor is significantly smaller, which means it’s easier to use. But more importantly the charging connector has no moving parts. A common failure on CCS chargers is that the locking pin breaks and the charger will no longer stay firmly attached to the vehicle causing charging issues. On the NACS adapter the locking pin is on the vehicle.

Charging infrastructure sees significantly more duty cycles than an individual car so it makes sense to move the wear part to the vehicle.