It's not a matter of power, it's a matter of growth and market saturation. Just look at companies like Zynga or Rovio, the moment their star game starts losing momentum, they get hurt way faster than regular gaming, due to the nature of their monetization.
Also, mobile gaming is too dependent of the asian market, and considering China adds and takes away draconian regulations on gaming all the time, many companies depending on the chinese market can go down fast.
This is not because one game in particular died in populatiry that the whole market is doomed. Revenues from mobile gaming only grew year by year in the last 5 years. If a game died, it just means people switched it to another, newer mobile game rather than stopped playing games on their devices forever.