I'm not sure what the purpose of the game is

The way I look at it, the real game is finding a way to optimize how to earn something from it (for both the devs and players). Just like all the other 'games' (aside from Steemmonsters which is an actual game) the life cycle is limited to the rewards since that is what it's basically about. Get in early and you'll make a profit (especially when freerolling) everyone who comes in late just provides some earnings for the old players. Once new players stop coming in it's basically game over and the ponzi structure collapses.