my personal experience - which is only anecdotal, i know - is that the people who struggle most with their application process either 1) severely need to revamp their resume, or 2) do not have the qualifications that they think they have.
it's a hard roll because you never really know what's holding someone back from a job offer to the point where they're jobless for a long period of time, but i've revised friends and family's resumes when they have trouble finding work and the shit i've seen is just appalling lol. they need to teach a resume-building class in high school/college or something... usually after the edits, finding work isn't so hard anymore. if revision doesn't work, then that usually means that you have to be willing to be paid less (which isn't always congruent with how skilled you are, sadly...)