Just carrying it in my pocket all day, nothing unusual. I might get a bit more lint forming or dust falling into my pocket than some people since I have a fairly active job but that applies to many others too. It's not just a USB-C thing either as I found micro USB to similarly build up stuff inside the port. Headphone jacks I never had a problem with when I had a phone or mp3 player with one, I guess they're less prone to this issue.