Voice chat with LLMs is a complete interface, and it's one that already works and can be slotted right into the product. You can prototype voice chat-based ordering app via no-code tools today, and without much effort going into it.

Dynamically generated interactive UIs are something people are barely beginning to experiment with; we don't know if current models can do them reliably for realistic problems, and how effort has to go into setting them up for any particular product. At this point, they're an expensive, conceptual solution, that doesn't scale.