The super-sub was trialed, then discarded because it was a crap idea.
Don't get me wrong; I'm fully supportive of the ICC & their endeavors to advance the game & make it even more appealing for spectators, more competitive, safer for players, & more profitable for all concerned.
However, wheather it was worth trying or not, it was still a crap idea - & most of us knew it from the outset.
If my memory serves me correctly, the decision to scrap the super-sub condition was made by the ICC early/mid last year..?
I also seem to recall that, even before that decision was made, a few teams agreed (pre-series) that neither side would use super-subs.
Makes me think that the super-sub debacle was dead in the water even before it was scrapped by the ICC.
The super sub was not benefitial was it was an advantage to the team that won the toss. Say both teams named batsmen as their super sub, and Team 1 won the toss on a batting beauty. Team 1 would bat and have their super sub in their line up, before taking out a batsman and putting in a bowler for the next innings. Team 2 would have to re-think their whole strategy though.
I wish they would return to the 15 overs of only two fielders outside the circle, was easier when you were watching at home. Although i guess the new ability of the captain to make fielding decisions gives more interest and it might be able to draw more players to one day cricket.