Use case:
by default Gutenberg is changing file names if they are uploading via Gutenberg Content Blocks (Images and Media) to some_hash.jpg wich is non good for SEO.
Temp solution is comment this function in file /modules/contrib/gutenberg/src/MediaUploader.php and add function getClientOriginalName:
$data = file_get_contents($uploaded_file->getPathname());
// $file_name = $this->getRandomFileName($uploaded_file->getClientOriginalExtension() ?: '');
// added line for keeping original filenames:
$file_name = $uploaded_file->getClientOriginalName();
$file = file_save_data($data, "{$directory}/{$file_name}", FileSystemInterface::EXISTS_RENAME);
This is just TEMPORARY solution, and must be checked after each Gutenberg module update !!