Immersion is an art that has been developed by many mediums over centuries. Obviously humans feel a need to connect and understand and do not need much besides the structure of a story and a world that has some familiarity to become immersed in the world. Now none of this is unique to games so most techniques to create an immersive world transfers over to games but what games can do is give players control. The book discusses using natural controls to keep the player immersed, I do agree that having bad controls or a system that frustrates the player can take them out of their immersion, however there are many more important aspects to immersion than the controls or all other mediums would have issues getting people to enjoy their content.
Mobile game in app purchases are some of the most predatory and manipulative systems in gaming. The app industry drowned itself in free apps to get more downloads, lost too much money, had to create too many free apps with adds to make their money back, conditioned users to not even look at paid apps, still needed to make money and now pump out games with massive advertisement budgets that are nearly unplayable without consistently paying piles of cash. There has been too much research on where in a gameplay loop to add in the micro transaction to make the most people to pay it, how long a player needs to have fun to want to pay money for it and exactly when a player will be addicted to a game. Its just bad.
As I already discussed there is a psychological element to keeping players playing. By giving rapidly declining progression and an achievable and very visible goal places just behind either a long grind or a small pay wall, the developers give a very enticing reward for a quick dip in the player’s wallet.