I think it's key you have 4 ports. I think the very small number of ports and requirement of dongles in order to get enough ports (and lack of USB-C hub) perpetuates USB.
If you have 1 or 2 USB-C ports odds are you'll need a dongle. Since the only USB-C dongles don't multiply ports, it'll have multiple USB ports. If you had a lot of USB-C ports, you'd likely get adapters and switch to USB-C as you upgraded things. Now, unless you can switch to wireless, you basically have to replace it with a USB device.
If you have 1 or 2 USB-C ports odds are you'll need a dongle. Since the only USB-C dongles don't multiply ports, it'll have multiple USB ports. If you had a lot of USB-C ports, you'd likely get adapters and switch to USB-C as you upgraded things. Now, unless you can switch to wireless, you basically have to replace it with a USB device.