Because noone likes waiting for their Tee.
$ fcat /tmp/largefile | itee | pv -r > /dev/zero [11.6GiB/s] $ fcat /tmp/largefile | itee /dev/zero | pv -r > /dev/zero [14.3GiB/s] $ fcat /tmp/largefile | tee | pv -r > /dev/zero [2.90GiB/s] $ fcat /tmp/largefile | tee /dev/zero | pv -r > /dev/zero [2.66GiB/s]