There's a similar question with answers here. However, the top answer there does not work for me:
If I use:
gsutil -m rsync -r gs://your-gcs-bucket s3://your-s3-bucket
It fails for me with:
The authorization header is malformed; the region 'us-east-1' is wrong; expecting 'eu-west-2'
Ok, rclone does work but, still, why not with gsutil rync?
I'm in London region by the way.