from man page:
-l limit
Limits the used bandwidth, specified in Kbit/s.
rsync --bwlimit=2OOK bigfile.iso name@server.org:path/in/destination sftp -l 200 bigfile.iso name@server.org:path/in/destination
https://www.redhat.com/en/blog/openssh-scp-deprecation-rhel-...
https://news.ycombinator.com/item?id=25005567