Yum Brands, including Taco Bell, has been refining drive-thru voice AI for two years, enhancing order accuracy and speed. Their digital strategy, which includes AI and systems like Poseidon, boosted digital sales to $30 billion. They've integrated Dragontail AI in over 7,000 Pizza Huts and plan to expand it to KFC. Other chains like Chipotle and Wendy's are also exploring AI.