On the drive your hierarchy is kept as it is if you use the external library feature. In this realease you can even browse the folder structure on mobile.

In Immich I did have to reorder all photos to their own albums, although I think there is a function that does this based on the folder structure. I did not try this however.

If you have an existing photo library somewhere on a drive, and load it in immich keeping its own folder structure. In the docker compose file you map the external library to the container.

Well, the point is I do not trust either. I am on apple now, but my experience with android is that there are apps you cannot uninstall.

On the other hand I have once tried a custom rom, but it was not a great experience. I do think I will need to try this again.

Which phone brand is recommendable at the moment? Fairphone uses android, which can hardly be trusted.