I see. A very good point. Thank you. This reminds me about the explanation of why do USB-C docks have separate USB-2 ports: because every USB-3 lane has a separate USB-2 sub-lane and these are left vacant after using USB-3 lanes to connect an SD card reader and a NIC internally.

By the way, about brave horizontal desktop PC designs, note a neighbor comment by c0balt mentions one, to it seems very nice, I would buy one immediately if a traveling salesman would knock my office door offering it without the mental overhead of having to order it and wait.