Dice the onion and bell pepper into 1/2-inch pieces, mince the garlic, drain and rinse the black beans, cut cream cheese into cubes, measure spices, and pat chicken dry with paper towels.
Heat olive oil in Dutch oven over medium heat, add onion and bell pepper, cook 5-6 minutes until softened, then add garlic and cook 1 minute until fragrant.
Add taco seasoning, cumin, chili powder, salt, and pepper to the vegetables, stir, and cook for 1 minute to toast the spices and release their flavors.
Place chicken breasts on top of vegetables, pour in chicken broth and diced tomatoes with their liquid, bring to a boil, then reduce to medium-low and simmer covered for 20-25 minutes until chicken reaches 165°F.
Remove chicken from pot, let rest 2-3 minutes, then use two forks to shred into bite-sized pieces.
Return shredded chicken to pot, add black beans, corn, and cream cheese cubes, simmer uncovered for 5 minutes, then stir vigorously to fully incorporate the cream cheese into a creamy broth.
Remove from heat, squeeze in lime juice, stir, and adjust seasonings to taste.
Ladle hot soup into bowls and top with shredded cheese, sour cream, cilantro, avocado, crushed tortilla chips, and any other desired toppings.