They're a way to slowly kill off physical media

not really, say i got my frend, i dont trust him with my game, i can just "lend" the vcart to him, i cant play my game cuz games use certs to identify different copies and my switch would get banned from nso cuz 2 copies online to Nintendo is classified as piracy, so they ban us!

by "i cant play my game" i mean switch restricts you from playing games that you lent out the vcart of, so you dont get banned, but once you take back that game, you can play it again, also iirc it works with eshop games only, or maybe even physical games too!