The game shines when practising new rule sets, particularly those with minimum scores — always pesky for new players. Having a computer opponent helps to get those practise games done so you can focus on actually playing the game.
I’ve been playing Riichi aka Japanese modern, which is more fun than I originally expected. I also tried the Korean game, which is played with just characters and dots, no bamboo tiles at all. Making pure hands is easier, but there are few tricks in the game.