While I agree that systemd does not play nicely with syslog, you quickly realize that journald can be exported as JSON, filtered, described as time ranges, chunked and easily imported into ELK. My users (mainly developers) with less sed/awk fu have come to rely on these features heavily. I'm not really sure what there is to miss about syslog or syslog-ng when you have a robust ELK+journald system.
Unfortunately it's also very slow. Text files don't have the many advantages you outline, but in everyday use they are much faster than the C journal API.