Except it's not succeeding in the "do it well" part. For example, accessibility? It's just two empty divs. No text-equivalent, so it's failing at the most basic level of accessibility. It's an updating widget, where's the ARIA roles to enable constant updates to assistive devices?
What's the rationale for CSS only? Considering progress is about waiting for things to happen, what is the timing based on? What triggers updates or changes?
Seems like an odd thing to have a progress bar, but no JavaScript events or methods to update it. Missing an important abstraction/interface. I'm not seeing the use cases where JavaScript won't be used to update the progress. A meta-refresh?
What's the rationale for CSS only? Considering progress is about waiting for things to happen, what is the timing based on? What triggers updates or changes?
Seems like an odd thing to have a progress bar, but no JavaScript events or methods to update it. Missing an important abstraction/interface. I'm not seeing the use cases where JavaScript won't be used to update the progress. A meta-refresh?