https://www.rsync.net/resources/notes/2021-q4-rsync.net_technotes.html
"We put the 's3cmd' command into our environment many years ago as a way to interact with, and transfer data between, rsync.net accounts and Amazon S3 buckets.
In 2022 this tool has been made superfluous by the wonderful 'rclone' command which does everything s3cmd ever did and much more."
and as a side note, rsync.net offers special pricing for rclone users.
https://rsync.net/products/rclone.html