All photos didn’t transfer to new phone?

I have just transferred all data and settings from my old phone to new phone using iCloud.

Does that mean you restored the iPhone from an iCloud backup of the old iPhone?

The iCloud Backup does not include the photos that are in iCloud Photo Library. YOu have to enable iCloud Photos in the Settings > Your Name > iCloud > Photos as well and wait for the photos to download to the new iPhone.

If you are having many photos in your iCloud Photos Library it may take a while, until they download from iCloud to the new iPhone. How to enable iCloud Photos again is described in this document (the second part): Get help with missing photos - Apple Support

If you now have signed up for enough iCloud storage and the additional storage is already available and showing in your iCloud storage display, wait for the photos to upload from your old iPhone to iCloud and from there to your new iPhone. It may take a few days to sync properly, depending on the size of your library.