The problem with google takeout is that it generates hundred of files to download as ZIP. I tried it in my own collection (800GB).
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.