This is very clearly not true.
There are tons of other aspects which involve other people related to careers. I've gone through panel interviews and if one person doesn't like you, it can sway where the interview goes and how it lands. I've gotten through many phone and test screenings, then HR, only to be stopped by a psycho manager. I was late to an interview once because the organizer did not send the meeting link. Of course, this looks bad and of course, I should have realized this. TF! I even interviewed three times once and the company notified me that I was not selected, only to call me two weeks later for another interview and I got the job. WTF?
I've had interviews where they were going to move forward only to stop because the budget no longer supported the position. They called me twice over a 9-mth period saying they were still interested. Dude gave me both his work and home numbers. What? I've been at the top of the interview chain only for the selection process to swerve to an existing employee who was not considered before, or someone came back or they knew someone from their sister company and went with them.
My current job HR kept wording her responses tentatively, "well, if you are selected" "if they decide to move forward". She was still saying this crap during the extensive background check (federally, internationally, Canada). I had gotten my paperwork back that everything had cleared and she was saying she had not been notified. She would have gotten shit before me. Seriously??
And none of this was in my control, it was always someone else.