"Avengers: Endgame" was released in 2019, and it did not specifically address Doctor Strange's character development in detail. However, it's essential to note that character development in movies and franchises like the Marvel Cinematic Universe (MCU) is often a cumulative process, with each installment contributing to the growth and evolution of characters.
Doctor Strange's character arc started in the 2016 film "Doctor Strange," where he was initially portrayed as a skilled yet arrogant neurosurgeon named Stephen Strange. After a car accident severely damaged his hands, he sought unconventional healing methods, leading him to become the Sorcerer Supreme and the protector of Earth's reality.
Throughout "Doctor Strange," Stephen Strange's arrogance was evident, but as he delved into the mystical arts and encountered powerful threats, he began to learn humility and the responsibility that came with his newfound abilities. By the end of "Doctor Strange," it was clear that his character had undergone significant growth.
In "Avengers: Infinity War" (2018), Doctor Strange's demeanor further displayed his maturity and selflessness as he made a difficult choice to surrender the Time Stone to Thanos to save Tony Stark/Iron Man's life. This decision showcased his understanding of the bigger picture and his willingness to make sacrifices for the greater good.
So, while "Avengers: Endgame" may have contributed to Doctor Strange's character development, it wasn't the sole reason for his less arrogant demeanor. His growth was a culmination of experiences across multiple films, each shaping his personality and values as the Sorcerer Supreme. As the MCU continues to expand, it is likely that Doctor Strange's character will continue to evolve and face new challenges, further shaping his personality and motivations.