Shifts to a pure money grab like many games. Declining rewards, especially for the gold pass. Find a more constructive way to pass the time. Their "challenge levels" ought to be called "lose your boosts levels". By their own statistics a fraction of 1% of players successfully complete these levels even with additional boosts. Does that sound like a "challenge"? Maybe if you had the option to skip it wouldn't be so blatant that the goal is to strip you of your accumulated boosts.