The "escape from reality to fiction" is termed escapism, see The Ethics of Escape by Coulombe. There has been empirical research on escapism as a coping mechanism since 1940s, see The Good and the Bad of Escaping to Virtual Reality in The Atlantic. Ethically, despite the negative connotation, it is not as harshly condemned as one might think. Tolkien, for example, wrote a passionate defense of escapism, On Fairy-Stories (1939) where he analogizes an escapist to an escaping prisoner:
“Evidently we are faced by a misuse of words, and also by a confusion of thought. Why should a man be scorned if, finding himself in prison, he tries to get out and go home? Or if, when he cannot do so, he thinks and talks about other topics than jailers and prison-walls? The world outside has not become less real because the prisoner cannot see it. In using Escape in this way the critics have chosen the wrong word, and, what is more, they are confusing, not always by sincere error, the Escape of the Prisoner with the Flight of the Deserter. Just so a Party-spokesman might have labeled departure from the misery of the Fuhrer's or any other Reich and even criticism of it as treachery... Not only do they confound the escape of the prisoner with the flight of the deserter; but they would seem to prefer the acquiescence of the "quisling" to the resistance of the patriot”.
In other words, Tolkien ascribes to the escapism the function of a spiritual outlet, and a means of resisting coercive ideologies that dictate "greater goods" to their own corrupt ends. On the other hand, the "children are starving in Africa" arguments against escapism sometimes tread dangerously close to the fallacy of relative privation. The idea is to turn a positive into a negative, a privation, by contrasting it with a bigger positive. The lesser good, a pastime, subtracts from doing a greater good, it is argued.
But why should it? In the OP example, why should we assume that Game of Thrones deprived distressed individuals, one by one or collectively, would be in a better position to tackle hunger in Africa than happier ones? Why should we assume that the released energy can be realistically harnessed towards a better use, and not wasted, or worse? Should we take toys away from children because they "could be" learning math instead? Why should one subtract from the other rather than add to it? The core intuition behind the privation arguments is the idea of a finite resource ("energy") that instigates a zero-sum game: for one side to win - the other must lose. But it is often unclear that the analogized resource is indeed finite, or that the game is zero-sum.
This is not to say that fiction can not become an abode of cloud heads and deserters as well. Most informal fallacies are plausibly valid when the context is right. Just as slippery slopes do abound in real life, so do zero-sum games and genuine privation. This is why it is said that all good is only good in good measure. When a following becomes obsessive, all-consuming, there is a finite resource that comes into play, the basic labor-hours and attention spans of us, humans. Dreyfus brings up Kierkegaard's apprehensions in criticizing another ethical danger of escapism into the "aesthetic sphere", corrupting influence of escape from action and commitment, in Kierkegaard on the Internet:
"The person in the aesthetic sphere keeps open all possibilities and has no fixed identity that could be threatened by disappointment, humiliation, or loss... We would therefore expect the aesthetic sphere to reveal that it was ultimately unliveable, and, indeed, Kierkegaard holds that, if one leaps into the aesthetic sphere with total commitment expecting it to give one’s life meaning, it is bound to break down. Without some way of telling the significant from the insignificant and the relevant from the irrelevant, everything becomes equally interesting and equally boring and one finds oneself back in the indifference of the present age... The temptation is to live in a world of stimulating
images and simulated commitments and thus to lead
a simulated life. As Kierkegaard says of the present age, “it transforms the task itself into an unreal feat of artifice, and reality into a theatre".
But before condemning the sin of privation one has to plausibly establish that privation is indeed a sin. That obsession with A consumes too much resources to the detriment of greater B. That B is indeed greater, and that cutting back on A will not itself have detrimental consequences, and can/will be plausibly redirected towards B. Mere "could be" is not enough. It may well be that Game of Thrones hype (along with many other hypes over shows and internet memes) does indeed rise to such obsessive levels, but establishing that requires a more thorough study and analysis, it is not plainly obvious.