There’s some sweeping statements in your comment there, mate! The USB-C cables that do transfer data can indeed reach those speeds. ‘Long white cables’ don’t signify a USB-C capable that is for charging only (unless I’ve missed a standard somewhere…). Also, I don’t think we can assume that ‘most’ USB-C cables are badly made; in my experience, if you pay good money, you get great cables, and even some of those that come with accessories are very well made. I’ve never experienced an issue personally.