Hemsworth is taking a break from acting for health concerns
https://www.bbc.com/news/entertainment-arts-63668310
He discovered he has a heightened risk of developing Alzheimer's so he's taking a break so he can spend more time with his family
I wish him all the best, he certainly deserves it after the work he's put into this franchise. Like over 10 movies all while maintaining the laborious physique of Thor, meaning he's been working in more strenuous conditions than most of the actors here.