I've seen so many job seekers venting on social media that they're applying for tons of jobs every week but never hearing back to be interviewed.
The simple reason that they're not hearing back is because their resume is not making it through the Applicant Tracking System (ATS for short.)
When a you apply for a job, most employers run that application and/or resume through their internal ATS before the resume is seen by a person. The ATS compares your resume to the job description in order to see how good a match you are for the job. If you're a good enough match, then your application may get moved forward to be seen by an actual person.
The ATS is looking for specific keywords that show up in the job description. It cannot read between the lines when it comes to assessing your resume. So, if the job description says that candidates need to have experience answering phones and providing customer service, then you need to have those words (answering phones and customer service) in your resume and/or application.
If you wrote in your resume that you have experience as an administrative assistant and assumed that someone would understand that an administrative assistant answers phones and provides customer service, then you've already lost out on getting the interview.
An ATS cannot interpret your resume. It can only determine your fit for the job based on the specific words you've included in your resume. This means that you must include the words "answer phones" and "customer service" somewhere in your resume to show that you have that experience.
This is why so many people are applying for a ton of positions but never hear back. They aren't taking the time to identify important keywords in the job description to include in their resume. (Which is called tailoring your resume.) Instead, they are taking one resume and using it to apply for all those different positions without making any modifications to show why they're a good fit for each position.
Think about the job application process as similar to playing darts. If you take a bunch of darts and chuck them at the dart board all at once, you're unlikely to get any to actually stick. That's basically you applying to 80 jobs with one, unchanged resume.
However, if you throw each dart individually, taking your time and lining up the shot with the dart board before throwing, you are much more likely to get that dart to hit the target and stick. Tailoring your resume by using the keywords from the job description (lining up the dart) will ensure that the Applicant Tracking System sees that you're a good match for the position and only then will your application be pushed forward for an interview.
Good luck out there!