Comment 35 for bug 64067

(In reply to comment #1)
> Many people have requested this, over the years, and there are probably a few
> complete patch sets implementing it. Why do you think it's best to add this to
> cp, when you can already use rsync as a cp-replacement?

Because then you have a dependency on rsync instead of cp... cp is pretty much
guaranteed to exist, rsync not as much. Also, rsync is in /usr/bin whereas cp
is in /bin. And rsync is 5 times larger.

Given that a lot of the time you're going to care about text mode cp and
progress is in early boot, you want to avoid all of the above.