If you just put up a job listing on Craigslist or some zero filter site, you get a lot of applications that are just unusable, from the absurd like “I have built a calculator app in JavaScript so I can design FPGAs” to the really sad like “I’ve just gotten out of prison after 20 years on a drug charge and I don’t know how to use a computer but maybe I can learn.” The recruiters job is to filter out bad applicants and the reason you need a human is that the applicants are actively trying to defeat the filter.