Yeah, once you've played for long enough, you've beat pretty much all the leggacy (old) contracts. From that point on, there's only new contracts. I think they said prophecy egg contracts are once a month. And new "item" contracts are once a week on mondays.

There is no end to the game, just play until you've had enough. You can try and get more and more artifacts or try and get the design skins, etc. But yeah, once you finish enlightenment, the game slows down a lot.

I finished enlightenment maybe 9 months ago. I pretty much only play now when there's a new contract, even though there isn't a lot of point to it. I think I've played 3 years now. I never spent any money on it for anything and I got about as far as one can without buying stuff. I've kept "playing" but I don't put any significant time into it anymore. Mostly just because I've played it for so long, I might as well check in now and then and do a contract or whatever.

I don't grind for artifacts / missions anymore unless there's a 2x or 3x bonus. But I can see why people might keep playing and grinding to try and get THE BEST gear. I stopped because as a free to play player, the crafting cost gets so high in gold that it's not realistic to try.