I've recently experienced this myself and it's insane. I grew up in what appears (at least to me) to be an average middle class life. I lived at home during college and commuted to my local community college, then state school to get my 4 year degree in CS
I grinded my ass off during college to get a good internship which led me to getting a $220k a year job at AWS with 0 connections. That one position was my lucky break that sent me into a world of connections I couldn't even fathom.
As a result of that job I moved to the bay area and made a bunch of friends both in and out of my field. Through that I've met VCs, mentors, recruiters, and many others who I could get a job interview through just by asking. I've also gotten a few other people jobs through direct referral. Don't get me wrong they still have to interview and perform well, but getting short listed for interviews is incredibly powerful.
I recently got a new job, full remote, amazing benefits, and higher salary than AWS (slightly less total comp) through a friend of a friend. Despite the tech market being awful I went from asking for a referral to signing an offer in 6 weeks with only 1.5 YOE. I'm no one special either, I just knew the right people to get interviews and then studied my ass off to pass them. Most people capable of passing wouldn't even get an interview because it's a numbers game.