Sad to hear that. Compared to previous versions of Photos.app, the functionality and strengths of the new app look completely off-track, very likely influenced by the iPhone's Photos app and project Marzipan introduced in Mojave if I'm not mistaken. I believe that Apple shouldn't have united these codebases and should've kept Photos.app on macOS a powerful and versatile organizer, to compensate something which a mobile app will suck at, by definition.

btw there's a separate TOPIC on GitHub for the tools that operate on iCloud Photos library, so if you'll ever need to repeat a one-way sync from iCloud, you can check e.g. https://github.com/steilerDev/icloud-photos-sync