I’m not sure about the cause either because I had my symptoms since before there were smartphones but they certainly make the compulsions worse for me sometimes.
For my photographic needs, I have started carrying around a small Reto camera. It’s completely without power so there’s also no flash and you have to be really mindful with what you’re shooting because film is expensive but I personally like the surprise you get when you can finally view the developed pictures 
I’ve been looking into getting one of those older instant film cameras as well. And I can definitely see how that can be a good deturrent to help you stop taking photos for reassurance. Once I pick up my phone, I tend to get into this state where I compulsively ruminate for hours and research things I don’t even care about. I ignore everyone around me and I cannot stop. I know once I switch back over to a dumbphone that will be less of a problem. If I have to consciously open a laptop instead, I am far more aware of what I’m doing and how long I am doing it for.
I have this theory that we really only need to spend 5-10 minutes on the internet at a time (after checking emails and messages). For me at least, I hit a point where I hit a wall and i’m done checking everything, but then I desperately try to come up with more reasons to stay on the computer. I could have already checked everything in 5 minutes and then easily spend four more hours checking things again and again and then going down a rabbit hole i don’t even care about. And I’m miserable doing it.