Simply exporting photos from one library to another in MacOS Photos will remove some of the features of the photos.
In MacOS Monterey, this feature has been added to Photos (https://support.apple.com/en-us/HT209528). How has this been done in previous MacOS versions?
I am looking for a solution that does not require purchasing software. And I am willing to do manual file or folder manipulation if this is the only way to do it. I do not have many photos to move.