That's fascinating. I know only a handful of people who got their jobs through cold applying. The majority of my friends were either referred by colleagues or received inbound recruiter email. That is, with the exception of my cohort in CS undergrad; we attended our university career fair for out entry into the workforce.
It's heartening to know that the cold apply method can be successful.
Every job I’ve ever gotten has been cold apply, with no degree except a GED high school diploma equivalent. You can certainly get jobs through cold apply, I get a job offer for basically every job that gets to the interview, even when I hadn’t worked as a dev I had two job offers I had to pick from. I like to think my passion, knowledge, and genuine interest shines through in my cover letters and my interviews.
Every one of my jobs has been cold applying. I don’t like maintaining networks explicitly because it takes a lot of work I have no interest in doing.
Cold applying works reasonably well IME, but you have to be able to nail the interviews for it to make sense. I'm great at what I do, I only apply to jobs which should be a good fit, and I still only get interviews 1-2% of the time. I then get offers 95% of the time, which keeps the process manageable.
I've gotten 3/4 of my tech jobs through cold applying though [0], and been offered many, many more. I know it's possible.
Ok that note, I love my current job, and I would've never found anything like it through my network. Cold applying was a literal game-changer in that regard.
[0] One was through Google Foo Bar, and one was through Codefights (now Codesignal or something), so those were slightly more tailored than cold applying.