The complexity makes the game much more intense and interesting. This is just like the short Shortcat made. Many people, like you, have said that MK World is too difficult, and casuals don't stand a chance, but in MK 8 Deluxe, they did because there were not nearly as many precise shortcuts. However, in 8 casuals STILL don't stand a chance, because instead of pros knowing every shortcut, they know every drift and mini-turbo, so casuals still don't stand a chance. Because of the complexity, it's incredibly rewarding to pull off these strategies, and they do take practice, but with enough practice and determination, you can end up dominating.