Edit: my first draft was harsher then it needed to be, sorry, long day.
First of all, nobody’s saying this is going to happen overnight. Secondly, traditional computing systems generate heat due to electrical resistance and inefficiencies in semiconducting transistors; the process of computation does not inherently require the generation of heat, nor cause it through some other means than electrical resistance. It’s not magic.
Superconduction and semiconduction are mutually exclusive - it’s in the name. A semiconductor has resistance properties midway between a conductor and an insulator. A superconductor exhibits no electrical resistance at all. A material can be a superconductor in one “direction” and a semiconductor in another, or a semiconductor can be “warped” into being a superconductor, but you can’t have electrons flowing in the same direction with some resistance and no resistance at the same time. There’s either resistance, or there’s not.
Finally, there is absolutely no reason that a transistor has to be made of a semiconducting material. They can be made of superconducting materials, and if they are then there’s no reason they’d generate heat beyond manufacturing defects.
Yes, I’m talking about a perfectly superconducting system and I’m not allowing for inefficiencies where components interface or component imperfections resulting in some small amount of resistance that generates heat; that would be a manufacturing defect and isn’t relevant. And of course this is all theoretical right now anyway; we don’t even know for sure if this is actually a breakthrough yet (even if it’s really beginning to look like it). We need to better understand the material and what applications it’s suited to before we can make concrete predictions on what impacts it will have. But everything I suggest is grounded in the way computer hardware actually works.