I can import pictures from my iPhone X to PHOTOS and edit them.
The edits will sync between your Mac and Photos only, if you are using iCloud Photo Library.
If your iPhone and the Mac are syncing their Photos Library with iCloud, the Photos Libraries on both devices will always be identical. Any edit or deletion or import you are doing on one of the synced devices will by updated in iCloud and sync to the other devices. (Note: Projects do not sync to iCloud Photo Library. Smart albums will not sync to the mobile devices).
But if you just import photos using My Photo Stream or a USB connection, the edits will remain local and not sync.
See: Keep your photos safely stored and up to date on all of your devices - Apple Support