I’m already hosting Immich, I feel it was the most painless to set up out of the three. There was a weird error with python modules with radicale and Nextcloud was a bit more complex to set up, but they were all relatively easy to get started with.

I particularly like Immich’s mobile app. I just clicked a few buttons and BOOM all my puotos are backed up (you can even change what albums to include and exclude, and duplicates are automatically removed e.g. if you have the same photo in multiple albums)