This film had so much potential but the editing and direction chose a slow burn rather than going straight into the tension. For instance, the killer (no spoilers, it's in the trailer) has three kills before they meet the protagonist; for a movie that runs at 90-ish minutes that's 10 minutes that could've been used for the second or third act.
There's no propulsion in the film. It all comes off as a character study when it also wants to be a thriller. I think Kendrick has good dorectorial skills, it's just this should be a genre flick with tension but rather it tries to do too much.