You can adjust the strength of the grip of the claw machine.
A friend of mine worked at an arcade.
He made the grip tighter whenever he had a surplus of prizes that nobody wanted and looser when he had good new stuff.
He wasn't even coy about it. He would tell the kids who always hung out at the arcade when he was doing it so they could go nuts.
I understand that with the claw machine the claw is unreliable, but the same claw is always equally unreliable and each time I play I could actually win, and my skill does affect that chance. With these games most of the time when you play there is a zero chance you could win, no mater how well you play.