Apple does a lot of things, being the second largest mobile phone manufacturer is one of them.

USB C is a decided standard. Tech decides standards to help progress, not impede it. When a better standard is required, it will be adapted. For now, it is a great standard that doesnt cause any bottlenecks. I have a feeling a new standard will be created before we even come close to a bottleneck with USB C, you are worrying about non-issues.

Edit: yeah, looks like usb c can charge a phone fast enough to damage a standard lithium ion phone battery, and supports data transfer rates of up to 10gb/s. Id say we're good in that department for a while.