If you are super lucky or a specialist in a super in demand niche field you send out 20 resumes and get 1-2 job offers. Thats a rejection rate of 90-95%.

If you are unlucky and not a specialist in an oversaturated field, then its not uncommon to have to send out 200 resumes to get 1-2 job offers. Thats a rejection rate of 99-99.5%

Why is it that 90-99.5% of jobs reject you because you lack something or are not their dream candidate, but then theres the one or two jobs who think your good/great and they hire you?

Getting a job is basically an anomaly. You get hired by the one or two companies that think you arent bad for some inexplicable reason. While dozens or hundreds of others just leave you hanging. This isnt a functioning system.