Season the chicken. Mix chili powder, cumin, smoked paprika, oregano, garlic powder, onion powder, salt, and pepper. Pat the chicken dry and rub evenly on both sides.
Load the slow cooker. Add onion, garlic, tomatoes with juices, and broth. Nestle the chicken in. Cover.
Cook low and slow. Cook on LOW for 4–5 hours or HIGH for 2.5–3.5 hours, until the chicken shreds easily. Don't overcook —dry chicken is not the vibe.
Shred and enrich. Remove chicken to a board and shred with two forks. Return it to the pot along with black beans and corn. Stir and cook on LOW for 15–20 minutes to warm through.
Brighten it up. Stir in lime juice and cilantro. Taste and adjust salt, pepper, and heat (a dash of hot sauce or more cayenne if you like it spicy).
Build your bowls. Spoon over warm rice. Top with cheese, salsa, avocado, a dollop of sour cream or Greek yogurt, and whatever else makes you happy.
Serve immediately. Garnish with extra lime wedges. Prepare for compliments you didn't ask for.