Revamp Potential?

Making cubes "less attractive" won't help because there is no alternative.
If cubes are half as good, or 1/10th as good, people will still have to use them if they want to get stronger.
KMS' cubes are worse than ours, with lower rank-up rates, and they still have people paying whatever it takes to get perfect potential on every item.
Worse cubes just lead to a smaller (relative) elite who manager to get "the best" potential. That's not balance. It's quite the opposite.

The alternative is to play the game and level up.
Getting stronger and getting better potentials is not the same thing although I can see why it can look that way. It simply highlights something game breaking when most everyone feels like they must have godly potentials to be any good.

When potential was just getting released it was not very attractive or rather, it was not overwhelming compared to other boosts. (that is why it was ok) The combination of things that kept it in check worked together to limit how much Pay2win could be involved. Without those many limiting factors, this particular system is corrupted to its core. We can debate the precise level of corruption but there is no escape from an infinite amount of Pay2win.

Even so, it is not an issue that can be classified as "bad." Certain players gain extra benefits, Nexon gets paid, free players get to keep playing and for better or worse, this is how Maple has evolved.