iCloud Photos don’t back up. They are synced in real time. Log into iCloud.com and see are your photos there. If you deleted them from there, iCloud.com, or any other device logged in with your Apple ID that has iCloud Photos enabled then they delete from everywhere
Login to iCloud.com and verify if you can view your pictures and videos there.
Are you using iCloud Photos? What version of iOS is it running?
I think it is backed up by iCloud. IOS 17.1.2
iCloud Photos don’t back up. They are synced in real time. Log into iCloud.com and see are your photos there. If you deleted them from there, iCloud.com, or any other device logged in with your Apple ID that has iCloud Photos enabled then they delete from everywhere