All of the games are built on the same foundation, with the exception of skin colour and weapon design. High game entry fees and a high learning curve for new users are discouraging new users from joining the system. Because of the unique teams they have, only early adopters are making a lot of money. The number of unique users registering each day is decreasing, indicating that the hype is fading.
Maybe you are right for those games that are simple and has same concept with some rugged projects that pretend to do p2e. There are lots of projects now doing p2e and cant say that they are good. But if you are gonna enter a p2e one then pick the highest rating with some good background or superb developers.