This is true. All photos in Photos library are stored essentially in a zip(?) file that you cannot browser via finder or shell. This is a major inconvenience f

This is true. All photos in Photos library are stored essentially in a zip(?) file that you cannot browser via finder or shell. This is a major inconvenience for me since my photo library is spread around multiple SSDs and NAS. In Lightroom, I just tell it where different photos are. In Photos App, if you want your photos to sync to iCloud, you need to copy them. This increases size of your Photos Library file. You can choose to Optimize storage but then you have one point of failure (iCloud). Right now, I use rsync to backup my photos to onsite NAS. And then I use Google Drive and iCloud for offsite backup. Google Drive works with photos where ever they are, SSD, NAS, etc. But iDrive needs all photos in Photos app to sync. BTW iDrive and Google Drive are not true backup solutions, so be careful if that is your only “backup” solution.