Again, you seem to fail to realize that there are many different motherboards out there and just because USB-C is the fastest ports on your motherboard doesn't mean it is the fastest port on everyone elses. You argument doesn't justify why someone buying a USB3.0 PCI-E card needs USB-C ports on that card or even justify why USB-C ports need to be on the back of a desktop PC. Just make the USB-A ports the fastest ports, so you can plug anything you want in and get as good of a connection as you can.
That nice. Do you think OP, or anyone else that us looking at buying just a PCI-E card with 4 USB-A ports has a bunch of external USB-C devices they will be plug in? You have on USB-C device, and some how that justifies having USB-C on the back of the desktop computer. Why? If you are plugging it into the back of the desktop, it's getting plugged in one and thats it. Use a USB-A to USB-C cable. There is no reason for USB-C on the back of a desktop.
I never said you use it with your desktop. I said you're argument for USB-C is so that you can plug in a dongle that gives you USB-A. That is specifically what you said you do. And it proves that the USB-C was useless since you are just converting it to USB-A anyway. It's a poor argument for USB-C if you're saying your primary use case is to plug in a dongle that gives you USB-A ports. Just use a USB-A port to begin with.
No, my comprehension is why are they wasting money on a PCI-E card with USB-C ports. Tell me this, what style port ON THE BACK OF A DESKTOP is more like to be used, a USB-A or a USB-C? Answer: USB-A. So why recommend OP waste money on a USB-C PCI-E card when all they want is to add some USB 3.0 ports?
I realize this is beyond your comprehension, but many people don't have finances to buy a bunch of stuff they don't use, like PCI-E cards with USB-C ports on them...