Well, we don't wanna run the same potions all the time and there's a limit to the number of Uber Potions we wanna create. These can be run more frequently, helping Composers and allowing GE Medals to actually be achievable.
It is cool that you do different stuff and i am sure composers like the idea but I suspect there is a flaw in that most people arent composers, or at least most I've talked to are not serious about composing, so I suspect reaching global targets might be a bit difficult
Not the case of course if the sellable chests have value