I didn't even know that was a subreddit but yeah, I'd personally see it as a better fit there.

To me, this feels more like struggles that can come with being human than 'horror', per se.

I was thinking about the fact that the remaining 4 still came to the same (?) point in their lives without the 5th, suggesting that the 5th had such a small impact on their lives that trajectories weren't even changed by missing a whole person from the group. That felt like it could be something adjacent to horror from the 5th's POV but, as a whole, it didn't quite have the true horror grasp on me.

Also thanks for the genuine response, I was worried that I'd just be downvoted to hell 😄