Is there room for optimizers to optimize? Of course, there always will be when you have a lot of options. Have I ever seen a Peace Cleric in actual play? No. I also rarely see much use of Bless, despite it being a cornerstone of optimizer builds, because "small but meaningful party wide bonus" is not a fun or exciting use of your Concentration slot.
The only way to remove optimization from the game entirely is to make every character have the same two or three basic actions, with no build variance or class differentiation at all. So instead we have a fairly happy balance where the accuracy is mostly bounded, within certain tolerances, and players still have meaningful choices in character builds and playstyles. People can break it if they really try, but they have to really try, not just play something that looks cool.