Heat olive oil in a skillet over medium heat; stir in onion and garlic. Cook and stir until the onion has softened and turned translucent, about 5 minutes. Stir in ground beef and sausage; cook until browned and crumbly, 5 to 7 minutes. Transfer mixture to a slow cooker.
Stir diced tomatoes, tomato paste, zucchini, carrots, red bell peppers, celery, green chile pepper, chili powder, broth powder, Worcestershire sauce, oregano, hot sauce, paprika, cumin, basil, salt, black pepper, and cayenne pepper into the slow cooker. Cook on Low until vegetables are tender, 6 to 8 hours.