How do I know? I did it. A couple years ago, I wanted to make a move to full-time remote work. I liked the people that I worked with, but I spent over a decade there, management started going downhill, and I could tell the company was on a trajectory of slow death. I spent HOURS almost every day for six months applying to jobs on LinkedIn. I restricted myself to positions that I thought I was actually qualified for without stretching. I avoided consulting/MSP companies. I probably applied to well over a hundred positions.
How many responses did I get? Zero. Not a single one. Occasionally, a recruiter would ping me and say they had a job opening that was a perfect fit. Every single time, it ended up being a contract position.
I DID eventually find my current job on LinkedIn, but only because I recognized the company name as one that a friend of mine moved to 6 months earlier. I called him up, asked him how it was, and he provided a referral. It dawned on me after I accepted the offer that every SINGLE job I have ever had was either through a friend's referral or because I knew the manager beforehand. The old adage, "it's who you know," is still as relevant as ever.