You
rsync of a directory with 2M small files takes forever.
ChatGPT
The bottleneck is per-file syscalls, not bandwidth. tar piped over ssh moves them as a single stream and is often several times faster; rsync becomes the right tool again on the second run, when only the differences matter.
You
Is there a simpler version that gets most of the benefit?
ChatGPT
Yes: do the first step, skip the automation, and revisit in a month. Most of the value is in the first step, and most of the cost is in making it repeatable before you know it is right.