The MCU will still be going in another 20 years so the example is okay since they don't plan on ending their franchises after a trilogy. With no end...
Tim didn't start out offering his services as a new Robin to Bruce (unless that was a later retcon).
Tim tried to get Dick to go back to being Robin...
Precisely. Everyone is the hero of their own story and everyone does what they do for reasons they *believe* are righteous. Hel, even hitler thought...