USB-C ports/cables have a few advantages I can see:

1) Reversible non-polarized mechanical plug. Easier to use.
2) Smaller size.
3) Spec'd for carrying higher electrical currents.
4) Type-C ports can implement optional higher-current features, for faster charging, and for powering peripherals.
5) "Alternate mode" electrical interfaces using the same host port.
6) Bi-directional current transfer capability: can be used to charge the laptop, and then later for the laptop to power/charge peripherals and smartphones.