The webcomic "Subnormality" shows a certain degree of talent. Notably it questions whether the authoress' efforts are futile because she is not materially wealthy. The bulk of strips seem to collectively pose a question: Is a fantasy worthwhile if it achieves material wealth for the author?
Most of the material relates to extreme power fantasy; e.g., a recurring character is a sphynx that appears to be an idealized version of the authoress. This ultra-powerful female character can devour normal humans and is typical of extreme power fantasy.
Another power fantasy depicts a secular humanist apocalypse that destroys all the traditional Christian ethics in the world.
Some strips deal with the alienation of modern society in an almost dignified manner, such as:
And yet, a few strips relate to the powerlessness of the job search, such as:
I must admit that the authoress obviously has considerable talent and intellectual maturity (even though I disagree with her leftist politics and secular humanism). However, her stark juxtaposition of the powerless feelings of the job search and the ultra-powerful feelings of crushing her enemies seems almost alarming. Her power fantasies appear to be dangerous or self-destructive because they appear to be keeping her in dysfunctional imbalance. This authoress appears to be keeping her own life in a dysfunctional state with her addiction to power fantasies. (That makes me wonder if all power fantasies are essentially dangerous drugs.)
The counter-argument is that fantasy has the potential to reveal deep truths about the self that cannot become apparent in mundane, responsible behavior. The world would have been a poorer place if J. R. R. Tolkien had refused to indulge in fantasy and had instead focused on his paycheck. However, there is a huge gap between potential and actual. Most fantasists are second-rate or third-rate hacks. Very few fantasists will be remembered with Tolkien.
Returning to material wealth, this answers the original question: Is a fantasy worthwhile if it achieves material wealth for the author?
The answer is "No, a fantasy is worthwhile if it reveals some truth for which the author intuits a need."