@EeveeEuphoria a USB-C connector costs 10 times as much as a micro-B connector (so $0.1 instead of $0.01)
but yeah, accessory side adoption is pretty easy, since it's mostly just a change in footprint
where the issue lies is on the host side, where you need controllers that can support USB-C, connectors are "one plug per connector" unlike USB 3.0, and the cables take ~60x longer to manufacture than regular internal USB cables.
My motherboard has a single USB-C port, and no extra connectors.