Unable to find and delete duplicate photos in Photos app using macOS Monterey

The best duplicates finder is probably within the trusted 3rd party app PowerPhotos ($35.) It gives lots of options for filtering duplicates--like comparing filename, date, resolution, etc. It also does lots more than find duplicates.

Another one that seems to work well is  PhotoSweeper ($15) which is cheaper but does less.

Beware of apps that claim to find duplicate files on your Mac-- some can wreak havoc on a Photos Library.

Yes, we need at least macOS 13 Ventura: Remove duplicate photos in Photos on Mac – Apple Support (AU)

On Monterey I would sort the photos by the capture date, so duplicates will be shown side-by-side.

I believe that duplicate detection feature was added to Photos in a version later than Monterey. Sorry, you'll have to find your duplicates by manual inspection or a third-party application.

re PowerPhotos.