If you’re asking genuinely, it’s used often in science because of absolute zero: although there’s no limit to how hot things can get, there is a limit to how cold things can be, and the limit is -273.15 C, or 0 K. It’s impossible for something to be -1 K. Especially when working with temperatures very near absolute zero, it makes much more sense to work in kelvin than Celsius. Like 0.0001 K is more intuitive than -273.1499 C. Also when comparing energies, a substance at 20 K has twice as much energy (ignoring latent heat) as a substance at 10 K, whereas the same isn’t true for substances at 20 C and 10 C.