Turn on iCloud Photos. You will never lose a photo. Problem resolved
Surprised people still do not do it
I own an iPhone 7 and several iPads...all with my same Apple ID. I tried using iCloud to backup iPhone 7 Photos a few years ago and had a management nightmare:
1)Enabling it on my iPhone somehow enabled it on all my iPads. Not good. I don't have dirty pix but I don't want my pix spread across all my iPads for anyone who picks up the iPad to see. And no, I do not use passcodes on my iDevices.
2)Once enabled on all my iDevices, I was able to disable it but it wasn't super simple.
3)I believe there is (or should be) a way to push the pix to iCloud as a general backup but it would be nice to have it available as some kind of remote viewing/access if I enter my Apple ID & pw with some app. Meaning: push the pix from my iPhone to iCloud and then hop on my iPad and use a certain app that prompts me for a username/pw to access the iCloud pix for that session.
4)Building on #1, once the iPads were all picking up my iPhone pix, I also started receiving pix on my iPhone that were taken from the iPads. Again, the management (and privacy) was not very easy to use.
5)it was very confusing figuring out what photos were taken on what devices because they were all mish moshed together.
Maybe some of these items have been fixed in the past 2-3 years but I didn't care for the process of iCloud and photos. Now put yourself in the shoes of people who do take dirty selfies and/or more private pix and you'll understand why some of us do/did not use iCloud.
If things have gotten far easier with iOS 12.x or 13.x, please let me know (with examples if you can) and maybe I'll give it another shot.