The LLMs mostly used older video models from a year ago that are capped at 10 second single shot clips. Newer video models like Seedance 2 go up to 15 seconds (Seedance 2.5 even up to 30 seconds) and they support multimodal references.

As a tool, I think those video models can be pretty amazing for artists as you can create things not possible before. Here is a music video made by an artist using Seedance 2: https://www.youtube.com/watch?v=yYfDJQxyHFg