this season in the NFL (I watch a ton of NFL) and college football (I mostly only watch byu and utah games) to keep track of the conversion rate on QB sneaks specifically. I eventually stopped keeping the exact number (after like 15 qb sneaks or so) but what I do know is that I have seen only 1 qb sneak not get the first down or touchdown. Funny thing is that when it didn't work (this was on 3rd down) the team did a qb sneak on 4th down and got the conversion.
I have seen a ton of passes and handoffs come up unsuccessful. It boggles my mind that offensive coordinators choose to run a play that is less likely to be successful. They have the stats/analytics to look at that tells them that the QB sneak is the most likely play to work on 3rd or 4th and a yard but they choose not to use it.
I would even run a qb sneak a couple times a game on 1st and 10. I bet it would result in 5 or 6 yards most of the time. (I would have a normal formation in these scenarios and the defense would be spread out)