I have applied for numerous jobs that not only was I extremely qualified for but should have had disabled veterans preference. I submitted not only the requested documentation but extras like licenses and certifications.
When I get denied it not only won't tell you why, it doesn't even say why exactly, simply that we can not determine if you are qualified or not. Thia despite the fact I submitted ample evidence of qualification for almost all the positions I aplplied. This is what interviews should be for.
I have seen postings up for one day implying they are not actually searching and likely already had a hire selected and just posted it to meet requirements. I sincerely believe most jobs you see come up have pre-selected hires.