> But, why would it get better to any significant extent?

Two years ago, the very best closed-source image model was unable to represent anything remotely realistic. Today, there's hundreds of open source models that can generate images that are literally indistinguishable from reality (like Flux). Not only that, there's an entire collection of tools and techniques around style transfer, facial reconstruction, pose control, etc. It's mindblowing, and every week there's a new paper making it even better. Some of that could have been more training data. Most of it wasn't.

I guess it's fair to extrapolate that same trend to video, since it's the arc text, audio and images have taken? No reason it would be different.