That's funny, 23 MiB/s is exactly what I get for reading systemd logs (on an NVME SSD). Is it supposed to be otherwise?
$ sudo journalctl -r | pv -a > /dev/null
[22.8MiB/s] $ sudo journalctl -r | pv -a > /dev/null
[22.8MiB/s] $ dd if=/dev/urandom of=test bs=1G count=1 iflag=fullblock
$ gzip -k test
$ zcat test.gz | pv -a >/dev/null
[ 228MiB/s]
$ sudo journalctl -r | pv -a >/dev/null
[13.1MiB/s]
$ gzip -k adventures-of-huckleberry-finn.txt
$ zcat adventures-of-huckleberry-finn.txt.gz | pv -a >/dev/null
[ 151MiB/s]
With real data, deflate maxes out somewhere around there either way, but that is a bit coincidental.
With modern CPUs getting increasingly smaller IPC improvements this will likely be pretty much the max decompression speed we can expect from gzip going forward.
I was getting the same numbers with text data I have scattered on my disk, but those were small, so I decided to generate a bigger file. But, yes, I agree a more robust benchmark would use a Mark Twain novel e.g.
--grep=