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.