USB-C will not do. it's nothing about brand, just USB-C 3.1 gen 1 doesn't have enough bandwidth to support 4k@60hz and USB3 transfer at the same time. it's either or.
there may be USB 3.1 gen 2 docks out there, but it doesn't matter because apple only use gen 1, even if you have a gen 2 dock, your port on your MacBook/pro will only be gen 1.
so as long as you want 4k@60hz and USB3 transfer speed at the same time, you need to go thunderbolt 3.
That is correct. But right at this moment, no Thunderbolt3 dock available.The only one that can do charging, 4K30 and USB3 and is compatible with new MBP is caldigit one. it's USB-C dock.