The day our generations own 'Scarlett Speedster', AKA Grant Gustin, made a choice to conclude his nine-year tenure on the once hit CW show beloved by fans internationally, we were saddened, but now we understand it was a decision that could not have been more mutually agreed upon. Grant Gustin was selected a decade ago to pick up the mantle as The Fastest Man Alive, and be the successor to the other hit CW show at the time, 'Arrow', where his character made their very first live-action debut in the shows second season.
In Fall of 2014, 'The Flash' premiered with resounding success and positive discourse, as the charm and unapologetic nerdy portrayal Grant Gustin brought to Barry Allen was beloved by fans. As with many shows, they peak fairly early in their first couple of seasons if they are lucky to receive that much, and the show becomes a former shell of itself which once fans of it use as a laughing stock -- this became very evident with 'The Flash'.
Grant Gustin had of course never spoke out publicly regarding the shows slow downfall, but nevertheless would still be a legitimate reason for his desire to hang up his cowl -- no, his reasoning for wanting to exit had revolved around a new change in his life... being a father.
Throughout Gustins time at Phoenix Fan Fusion while on a panel, Grant disclosed his personal reason for why he chose to depart from the show:
"Gustin shared it was very overwhelming to be a 23-year-old that was leading that type of show. He tried to not think about it to keep the anxiety in check. As he grew older he realized with age, his world kept changing and knew it was time to wrap the show when he thought of all the bedtimes he was missing for his daughter. He didn’t want to ever do the show at less than 100%, so it was time." - Grant Gustin, The Direct
When you take up a role that prominent with so much confidence not just instilled in yourself from fans in trust that you will do a good job, but the confidence you personally instill in yourself, it can turn out to reveal itself as a problematic job to do, especially in Gustin's case, who at the time was 23 years old. As the years went by, Grant grew in various aspects, most significantaly was that he got married and had a daughter.
This change brought up a realization of a threshold in Grant's work he wasn't willing to cross for the sake of 'The Flash', as he did not want to be so occupied while being a father that his portrayal of Barry Allen had to be given less than 100%, but he wanted to be a devoted father as well. He truly still cares about this character despite what others may feel or say about the show he is playing in.
Legally Grant could have exitted the show because of contracts, but emotionally and personally, he left to be a father.