It’s for personal satisfaction. At some point, you can’t physically move the cube any faster, but rather you learn new algorithm to save the steps. For example

It’s for personal satisfaction. At some point, you can’t physically move the cube any faster, but rather you learn new algorithm to save the steps. For example, you could solve the final layer by repeating 3 algorithms. Or you could learn about 100 algorithms for 100 permutations. At higher level, you would know that using A algorithm would be faster than B because the one next to it is easier to perform. You could look in blind cube where you look at the cube, memorize it then solve it while blindfolded.