100% the lightning port is more durable. Take a look inside a usbc receptacle some time, there’s a thin little plastic part that all the electrical contacts are supported by. The plastic tongue is easy to break and is flexible enough that you can pull contacts up off it and bend them out of place when you go to clean the pocket lint out of it (if you can even find something thin enough to get in there).

I’ll go a step further: the lightning cable is designed to break and that’s good. No, it’s not designed to break so that apple can sell you an overpriced wire, it’s designed to break so that you can replace the wire instead of the port on the phone. There’s a little pcb built into the end of the cable that will break before the port if someone sits on the phone or whatever. It’s also the reason why over time they need to be “held right” to charge. It’s not dirty contacts on the cable or port, it’s the wire connections to the pcb in the cable that need to be held right.

Usbc is the opposite. It makes a really strong annular connection to the port and can very easily rip the receptacle right up off its board just with the leverage you can put on the wire.