is the hiring process really a month long/ sometimes longer?

so theres a job fair later on today hiring for ccas and rcas, dont really know what i wanna do yet but ill take what i can get since ive been unemployed for 2 months now and the holidays are here so generally id like a lot of hours since im broke as shit? i type on my google search engine "how long does usps take to hire" and people on reddit say crazy shit like 3 months LMAO why would i even bother? is it generally expected that youd only apply if youre already currently at another job and just looking to change? ive had a job interview and hire me within 3 days, and was able to work within the week. anything over a month seems a bit crazy although

it says theyll do prescreening and fingerprints on site during the event so would that speed it up?