Interesting Concept: There is a sweet spot somewhere
Mathematically, there is a sweet spot somewhere in which this game is 100% balanced. There are too many variables to truly know where this spot it, but in theory, there HAS to be this "spot" that exists.
To have the 138 champions, 200+ items, and all the new runes/combinations line up to hit this point would be pretty much impossible, but just knowing that sweet spot exists somewhere is interesting.
I think there is a certain amount of subjectivity to "balance" but there is also a literal definition as well, and thats what I think we're looking at here.