You're forgetting the cost of surrendering your (illusion of) civil liberties by voluntarily disclosing private information about yourself to the government.
I have Global Entry. The application form didn't ask for anything more than what a typical job or rental application would (basically, employment and address history going back a few years).
My Global Entry enrollment "interview" consisted of "Put your hand on the scanner. Now look at the camera. OK, you'll get your Known Traveler Number in an email later today, and a card you can keep with you in the mail in about a week."
The CBP people who do GE generally seem to be on a whole different level of efficiency and understanding-actual-security compared to the average TSA blueshirt at the airport.
If you have traveled internationally, you've already given up the vast majority of the information required by Global Entry. I've had to submit to medical examinations, interrogations, and forced fingerprinting to enter some countries. Most of that stuff is sent back to the US to verify your identity.