Place chicken breasts in the bottom of the slow cooker.
Add beans, crushed tomatoes, diced onion, minced garlic, chopped celery, chicken broth, Buffalo sauce, chili powder, cumin, salt, and pepper.
Gently stir ingredients to combine without breaking up the chicken.
Cover and cook on low for 6 to 7 hours or high for 3 to 4 hours until chicken is tender and cooked through.
Remove chicken and shred with two forks.
Return shredded chicken to slow cooker and stir well.
If using, add cream cheese and stir until melted and fully incorporated.
Taste and adjust seasoning or add extra Buffalo sauce for more heat if desired.
Let chili rest for 10 to 15 minutes before serving for best flavor.