I have, unfortunately, been lax about managing all my photos: not so much that I haven't been careful with them when I knew where they were—I do have an actual backup regimen—but that somewhere along the line I lost track of where a large tranche of them were, because I hadn't centralized how I was storing them.
As a consequence, I don't have any of the several dozen photos I took between 2001 (when I first bought a digital camera) and 2013, when I got my first replaceable-lens digital camera and reasonably ubiquitous cellphone. This actually makes me really sad sometimes—I had pictures of friends who are no longer around that I'll never get back.
Sigh.
Anyway, for a good long while, I was using Shotwell to manage things. It was…fine. Not heavily maintained, but I don't have exotic needs. I would periodically download everything from iCloud (since my iPhone is what I take the majority of pictures with) and dump it in there. It was awkward, but basically worked.
Then for the last year or so, I've been lazy and just relied on iCloud Photos—again, the iPhone is my primary camera, so that was easy, and if I took pictures with the Sony, it was usually because of a trip, so I wasn't too likely to forget to upload things. But I hadn't done that since our trip to Iceland last September.
Of course, iCloud Photos doesn't handle a lot of stuff—like RAW images—so I still had the spectre of having to maintain copies of some things locally hovering over my next trip.
And then a few months ago I heard about Immich, and was intrigued, but didn't act on it. And then I saw a video from Lawrence Systems about it:
And that convinced me to try it, and so far it's been absolutely worth it. I've got everything moved into it from iCloud Photos, as well as all the RAW images that I kept copies of. It even made it reasonable to take the "dump everything in, sort it out later" approach—it has good support for de-duplicating images, and although it was tedious, I was able to get rid of every lower-quality JPEG in favor of the RAW versions of things, as well as lower-res copies of stuff that I ended up with. Images from the mobile devices are automatically uploaded whenever I'm on the home WiFi, so I can feel secure about that.
It's got a good track record of bug fixes and new features, but at some level one has to understand that that is proportional to either how new the project is (when it's running just on sheer enthusiasm), or how well compensated the author or authors are for their time. As a consequence, I plan to "purchase" it before the end of the year—it's Free Software, but I'd be a fool to not help provide material support.