Online job platforms like Monster, Indeed, Glassdoor, etc. have changed things significantly. If you can apply in one click, or just a simple form, it's trivial to send out 50 applications a day. Those easy-apply jobs will of course get hundreds of applicants, requiring an even wider net to stand a statistical chance.
My job search looked a bit like that. Luckily, I had just a few connections from grad school, which of course immediately led to interviews and offers while my hundreds of one-click applications lead to form rejections or have been ghosted. But without those connections, I'm not sure what choice I would have.