> In chess, by contrast, there is a relatively large search space but each move can be evaluated and rewarded accordingly. That just isn’t the case for the Rubik’s Cube.
I don't follow this at all -- how do you reward an individual chess move other than by using a reward system that may or may not be anywhere near fully accurate like counting material? Seems pretty similar to solving a Rubik's cube.
https://en.wikipedia.org/wiki/Computer_chess#Leaf_evaluation
That said, I think I agree with you. The Rubik's cube is amusing because it literally is just permuting numbers. You can build a transversal set where you quite literally just pick the permutations in order to get back to sorted. I haven't gone through the effort of building up the transversal set, yet, but http://taeric.github.io/cube-permutations-1.html was where I started playing with the idea.
I mean, yes, you can get more complicated. And no, I have not gone through the effort yet to see how much time the set takes to build up. Pretty sure it won't take long, though.
If you just count material and look 30 moves ahead you will not get outvalued by a human. The reward system does not need to be perfect to be useful, but there does need to be one.