There's nothing more discouraging when playing a game than becoming maxed out and reaching the end of the game. When there's no need to collect money or get more levels the game just starts becoming stale really fast and everything starts to lose sense. I used to play this game called Tibia which had infinite progression and it was great feature. It was easy to reach a decent level but from there on every level was just progressively harder and harder, and as the higher you would get you could take months just to acquire one level more. It didn't really matter that it was so slow because it was much better than reaching a cap and the reason to go out and level was never lost. Also, money was always required to be able to hunt and level so the reason to collect money wasn't lost either. They had the perfect vicious circle for players to play for years and never get bored.I believe that the level progression curve can be tweaked in the way that new players can become decent and competitive relatively fast, but long old players should always be able to become a little bit stronger and have a little bit of an edge over new players.