Interviews allow just a little time for strangers to attempt to sync up and get a sense of each other.
Actual jobs offer much more time for people to learn to sync and communicate.
Also, on both sides of the interview table, people have varying strengths when it comes to short and long term communication skills. Plenty of interviewers are not good at interviewing, just as plenty of candidates are not good at their side of the process.
In short, interviews are a very poor approach to choosing who belongs long term.
Ultimately, regardless of the interview process used, every job is ultimately a long term “try and see” interview. You only know how someone fits by trying them for a while.