people are playing these games just for the sake of reward and that's it.
they don't play it because it's fun, when it comes to fun aspect of playing the game I think we can pretty much say that people out there are willing to shell out some money to play a game that's actually fun but the opposite is happening to these gamefi projects.
they pay people to play their game to grow their userbase and then get funding from investors, in a nutshell it's just a business scheme where the player are the product.
therefore that's why these game never sustaining in the first place, because the game itself was made not to be a long term product, most of the game also just reskinned dead game that doesn't sell before.