There are USB-C peripherals though. I just did a quick check for "USB-C " (tried mouse, keyboard, and drive) and found plenty of options. The USB-A devices are frequently cheaper, probably because USB-A compliance is a lot easier than USB-C compliance, which translates to cheaper products.
If the market doesn't jump to support USB-C, it's probably because it's either too expensive or customers don't care. If neither is the case, the companies that make USB-C devices would make a killing and everyone else would rush to catch up.
I personally slightly prefer USB-C, but I don't need everything to be USB-C. USB-A still works fine, and they work especially well w/ my older devices. What benefits do I get by switching to USB-C? Having everything the same is nice, but how much is that actually worth when it comes to extra costs?