I think is not zero it it's possible interpretation as accusatory

I'm not sure how to ask that won't in some way feel like either a demand for action or and accusation of abandonment.

Maybe just look at the commit history. If nothing has been committed in 6-12 months and if the code is not great as is then fork or move on.

I've written a couple of libs I consider done. They are still super useful but there's nothing I want to add for 2-3 yrs now. They are not abandoned