whenever i read about the difficulties in building an AI, most of them seem to happen due to the massive amount of options available, however that means they are still brute-forcing the problem and not approaching it with true learning, no human will have even seen a small portion of those 2*10^170 moves, same for chess's 10^47 set of moves, why because they don't make sense in the scheme of the game, or compared to how you learned the game viewed as non- optimal,
I suppose its the difference between playing for a garenteed win (by knowing all possible option paths you can force the human to loose), or by playing as a equal, then improving to win most of the time, (learning patterns and strategies that win, and counters to most likely to occur moves, while being able to plan out a few plays ahead to gain an advantage,
Why i say this is, real AI cannot be brute forced, you can teach it every possible bit of music it can play with a midi interface, you can even begin to train it on what sounds good, but change something and you need to go back to the drawing board, same way that teaching it to play go from chess took many years, when they have something that can go from playing checkers to uno to 20 questions with a few minutes / few hours of learning while confused working out the rules, that will be a bigger goal post in my head,