A resume gets you in the door. The interview gets you the job.
Someone who is great at interviewing, but lacking a qualification or two, will almost always get hired over someone who is fully qualified but a terrible interviewer.
Because job descriptions are wish lists. They are an idealized version of the candidate. By the time you get in the door for an interview an employer has already made a determination that you can likely do the job. What they want to get a sense of in the interview is…you.