As someone looking to exfiltrate my photos from Google, I'm about to trial Immich, and I really appreciate you sharing your experience. Sounds like it's a good next step for me.
https://takeout.google.com/?pli=1 https://github.com/simulot/immich-go
https://metadatafixer.com/learn/how-to-download-google-takeo...
I struggled with Immich, I didn't like the rclone option. I'm intending to go back to Immich but my first priority was to get the stuff out of Google. That's done, so with all my free time (ha!) I can get the family Immich going.