Nice study burenka. I think even there are many P2E games online, and most of them play the games assuming they will earn a lot by playing the games. But thats not the case. Most of them spend hours and hours in front of the screen and get paid very small amount of money compared to the efford they put into play and I think it does not even cover the electricity cost. But most of the time early adopters to the game dominate the game while accumulating lots of profit.
But you forget about the entertainment factor. Usually with games like that, as long as you are already into the game, and you have a lot of time you can pretty much play it forever if you want to, I think it is worth it. Just to have some hours of enjoyment by playing a game and interact with people that are playing it. I know people who play Half Life 2 or Team Fortress 2 for many years, and they have hundreds of hours of fun in those games, without ever earning a single penny.