The ending of Toy Story 4 is considered sad by many because it marks the bittersweet departure of Woody from Andy and Bonnie's lives.
Woody, the beloved cowboy toy, has been a constant presence in Andy's life since the first movie. Throughout the series, he has experienced numerous adventures and formed deep bonds with his fellow toys.
In Toy Story 4, Woody encounters Forky, a spork-turned-toy who struggles to accept his identity. Woody's desire to help Forky find his purpose leads him on a journey that ultimately results in him choosing to stay with Bo Peep, a porcelain shepherdess he had a crush on in the past.
This decision, while fulfilling for Woody, leaves a void in the lives of Andy and Bonnie. The audience, having witnessed Woody's unwavering loyalty and dedication to his human companions, feels the sadness of this separation.
The ending also hints at a sense of closure and acceptance. Andy, now a young adult, has moved on with his life, leaving his toys behind. Woody's departure from Bonnie's room signifies a similar transition, acknowledging that even the most cherished toys eventually reach a point where they must move on.
The film's creators skillfully weave together themes of growth, change, and letting go, leaving viewers with a bittersweet feeling of both sadness and hope.