Long USB lead to a hub under the desk and the backup drives off that.
Then it looks like a squid wrestling contest with around 15 squid seeing as hub and drives are all powered.
But the new ssd, not sure what to do with that but have an idea. (not powered).
Edit. Multiple cables can be loomed with expandable braid or spiral wrap. I tend to keep spiral wrap where it is out of sight and easy to break out cables feeding a stack of kit and use the braid where it can be visible. Braided wrap can fray a lot, use enough so you can tuck in the ends back into the braid and you will have a neat finish. Braid comes in various diameters as does spiral wrap.
Though the headphone socket on the 24 is a pain for this.
While I'm not using an iMac as my main computer. I keep everything I don't need ready access to. Mounted behind my desk. I also keep cables wrapped together and routed around my desk. To minimize the visual appearance of anything "messy".
My 3.5” Time Machine drive sits on a nearby shelf out of sight alongside the power brick. I velcroed the power and USB-C cables together and run them neatly off the desk.