I'm saying your contribution is outdated and irrelevant, and my primary intention in commenting is to label it as such for any passers-by who might think you're talking about the current state Immich.
That sad, I'm happy to answer your questions. I've run Immich in docker for 3 years with automatic updates through watchtower. Updates are frequent but require no effort from me and have never broken anything, nor is there an "update script" to fail. Nor have I encountered "corruption" at any point. I do back up the database and my photo library.
I'm glad you're happy with your solution, you can share it without disparaging other solutions you're unfamiliar with.
I'm glad you're happy with it, and perhaps Immich will continue to remain secure. 3 years is comforting.
I will note that the last solution I used was fine for over a decade before it broke (and eventually the project died). For much of the time I was using it, it was the primary open source self hosting solution.
So one of my criteria is: "If the project dies, can I maintain it?" Obviously, I can't use that approach for everything (limited skills and time) - I do use NextCloud, for instance (which, BTW, is fairly painful for some of the reasons I listed above). But wherever I can (and wherever it's important), it's best to develop your own stack.
Best to think in the long term. But yes, for sure, there are down sides to my approach.