There’s definitely some works that have unnecessary sex scenes; it’s more obvious in movies, though. A lot of the time, the entire romance subplot is utterly unnecessary, and sometimes horribly executed on top of that. Remember The Hobbit, now imagine they also had a sex scene!
In at least a few cases, the “unnecessary” sex scene is necessary to get the film the rating that the director feels is appropriate for the film, because violence and adult themes don’t always get the rating they probably should and the MPAA is a bunch of prudes about sex.
That would feel weird in Hobbit because it’s a story he wrote for his kid. At the same time, I find George RR Martin’s critique of that aspect of LOTR valid. He said something along the lines of “It’s a neat world, but it doesn’t feel real. Can you imagine dwarves having sex?” Meanwhile, due to its grit, the GoT world feels very believable. Humans are messy, primal creatures at the core.
