Satechi, who makes some of the sleekest accessories, is coming out with a USB-C Clamp Hub specifically for the 2021 iMac (24-inch)—sorry iMacs made in 2020 or earlier. To match the 2021 iMac, USB-C Clamp Hub has a modern, aluminum design. It’s got a USB-C data port, three USB-A 3.0 data ports, micro/SD card readers, and an adjustable knob to clamp onto your iMac. It’s not shipping until mid-September, but if you pre-order it now, you can get receive 15% off with the code IMAC15.
I had a similar Satechi Clamp Hub for my iMac Pro and it worked great. The question is whether the convenience of easy access to those ports is enough to justify making the front of your fancy new iMac look kind of ugly.