Having now read a lot more on these topics, I like the idea of the ThunderBolt-3 ports which use a USB-C type connector.

A "docking hub" using that connector could work in one of at least two fundamentally different ways:

(1) The hub could use USB3 protocols, with or without a DisplayPort overlay. This limits total cable bandwidth of all attached devices to the USB3.1 10gb/sec maximum throughput. Multiple USB ports require a built-in USB hub chip. Most/all stuff out there today probably works this way. If the DisplayPort feature is used simultaneously, it could occupy as much as 5.6gbit/sec of the original 10gbit/sec cable bandwidth, slowing down transfers to/from any USB3 devices on the same cable.

(2) The hub could instead use PCIe protocols, again with or without a DisplayPort overlay. This increases total cable bandwidth up to 40gb/sec for all attached devices. In order to provide one or more USB ports, a PCIe USB host adapter chip (XHCI for USB3) would be needed inside the "hub". Other PCIe host adapters could also be incorporated, giving additional "native" SATA/eSATA for example using an AHCI chip. And/or even some physical desktop machine style PCIe or PCI slots.