Well, the game must have some valuable game items, buying improvements, buying weapons and so on ... Only in this case the blockchain will make sense
As you know, now all games meet these requirements. In many there is everything you called.
You are right, now all games contain built-in purchases, various game assets, money and so on. Therefore, I think there are development teams that can not develop a blockchain themselves. They will need help and support from BIT.GAME