I read an interesting post about this on the worldbuilding subreddit that I was going to "cross post" here for the sake of having more content that isn't just me talking about my own stuff. Unfortunately I can't find the post again, so I'll just summarize it and put my own thoughts.
Basically, zombies and vampires resonate strongly with the modern mind. Zombies represent the loss of individuality and subsumption into the horde. Vampires represent a parasitic aristocracy literally sucking the life out of those beneath them. But werewolves don't really stand for something that modern man can latch onto.
Some of the comments suggested that lycanthropy is usually depicted as a part time transformation, so getting bitten doesn't mean a total loss of self or humanity, compared to becoming a zombie or vampire which is usually permanent, so it's not as impactful as the other two.
It's also possible werewolves represent the dangers of the wilderness, getting attacked or eaten by wild animals (wolves especially) or dying of exposure. In the past those were problems faced by more people, so the trope resonated more, but modern advancements have pushed the savage wilderness back, allowing humans to live in relative comfort without such fears.
The last point that was brought up approaches how I imagine lycanthropy, namely man's inhumanity to man, the worry that beneath a thin veneer of social convention we're all just naked apes acting on the same savage instincts that our hairier tree-dwelling cousins do. Werewolves represent what happens when that thin veneer is stripped away. Indeed, there's a Latin phrase that embodies this. Homo homini lupus (man is a wolf to man).
But I think I'd take the idea in a slightly different direction. What if we start with the conceit that werewolves are humans who turn into literal regular wolves every month, as opposed to superpowered bipedal wolf men. Wolves who think and act like the nonsapient animals they are in real life. Real wolves don't maul everything that moves. A wolf is more likely to run away at the sight of a human. A wolf who isn't currently starving isn't going to risk life or limb on a meal that fights back. So what if when a werewolf turns, he just slinks off into a corner and sleeps, or if hungry, seeks less risky prey than a human.
For a brief window of time, a human gets to experience a life without dwelling on the past or worrying about the future. He simply acts, without worrying about the morality of his actions, because he's an animal, and animals don't have a moral framework.
Perhaps some part of his humanity is accessible while transformed, but it's a faint echo of emotions evoked by familiar sights and sounds and smells. He has no idea what a house or a couch are, and even less what ownership is, but he recognizes his human house and human couch as places of rest and safety. So he just quietly curls up on his couch and, for the first time this month, gets a good night's sleep because he's incapable of worrying.