Gutenberg gallery file titles – bug or by design?

In the classic editor, if I name my files locally as I want before upload, the filename is copied verbatim to the media title and can be quickly and easily copied to the caption during the gallery creation process.

In the block editor, if I upload files directly into a gallery block, they are all hyphenated (e.g. file this is my dog.jpeg becomes titled this-is-my-dog). Is this a bug or by design (if the latter, why?)?

To add to the lack of usability, I then have to retype all the captions in the gallery, which completely negates the ease of creating the thing in the first place.