Why Is Date Taken Empty in Windows?
An empty Date Taken column means the photos have no date inside them. Windows is not hiding it.
Because there is nothing to show. Windows reads Date Taken from inside the file, and for those photos that field is blank. Explorer is not failing or hiding anything.
Google Takeout exports are the usual cause. Google moves the date out of the photo and into a .json file beside it, and Windows does not read those. Photos from WhatsApp, screenshots, and web downloads are usually blank too.
Filling the column means writing the date into each file. Takeout JSON Metadata Fixer does that for a whole folder in one go, and Explorer shows the dates immediately afterwards. It runs on your own computer and is free for your first 500 photos.