The sun actually is moving, but that doesn’t account for the relative motion resulting in a “sunrise”.
Language is human centric, and always will be. There wasn’t a need or a will to change the term post-Copernicus.
And convenience centric. There really is no quick phrase for what’s really happening. So sun rise it is.
And whether or not it’s moving is arbitrary anyway. It’s all dependent on your coordinate definition. It’s not like you can go out in space and there’s a giant pair of X and Y axes out there.