alt Hacker NewsPretty much all the photos in Apple/Google photos are going to be JPEG and HEIF which do support EXIF. But both services basically will not touch what came out of the camera at all. If you add a description or date, it gets stored externally to the image so when you export your data, those changes are lost. Or they get dumped in a JSON file requiring you to use some custom script to handle it.
Not touching the image for metadata changes is a good thing as that makes backups more efficient/simpler. Embedded metadata is also a security issue as users may share more information than they realize which is why it is common to strip it automatically in many places.