This is the major issue, most free and open technology is not marketed as well; isn't anywhere near as user friendly and often times takes a lot more time and effort to setup. Most people don't care enough for that.

Okay, secure E2EE backups we've more or less perfected for a while. There's good F/LOSS solutions for that. And if you're willing to pay a bit, thinks like Backblaze come to mind. In other areas it's true that open-source stuff is less polished, but not backups. I mean, a few months back Apple had a regression where they were un-deleting people's photos, that's pretty nasty.

The 35mm film camera, developed by a photo lab, with pictures stored in a show e box

Modern devices are so locked down that you couldn't build such software even if you wanted to.

Those corporations are part of the problem, not the solution.

Plug in a phone, run adb pull /storage/emulated/self/DCIM or wherever that Android garbage OS stores photos these days.

Local, doesn't need encryption since there's no middle in E2E that you need protection against, and simple.

Grandma can setup ~/.zshrc `alias bak=cd ~/phonephotos && adb pull ...` to make it even simpler.

I turnips were watches, I'd wear one by my side.