Most PC cooling solutions cool your CPU/GPU/memory using fans or water that exchange the generated heat with the surrounding air. This means you can never cool the components to any lower temperature than the surrounding ambient air temperature.
There are people who push those boundaries to hyper-low temperatures by pouring liquid nitrogen or other hyper-cool liquids into specially designed heatsinks; but it introduces a new set of issues. A big issue for cooling below ambient temperature is condensation.
As soon as a surface is cooler than the surrounding air temperature dew point, then water from the air may start forming as condensation on the surface. We see this every summer on the sides of iced drinks. As anyone with electronics experience knows, water and electricity don’t mix.
Many people have experimented with sub-ambient cooling solutions before. The latest is EKWB with their EK-QuantumX Delta TEC EVO water block. Instead of using just a normal water block connected to a radiator, this solution uses a Thermoelectric Cooler (TEC) with a controller that then dissipates that heat through a radiator.
It’s an interesting, and surprisingly complex problem.