syslog(3) is a sort of std{log,debug}. You can tee it to a vt if needed. (Of course with systemd you have weed through configuration.) But stderr was designed

syslog(3) is a sort of std{log,debug}. You can tee it to a vt if needed. (Of course with systemd you have weed through configuration.) But stderr was designed to be seen on terminal regardless of piping or logging. It’s its purpose, so that a pipe user could see what’s wrong or what’s up. There may be a programmatic need to read stderr, but mixing it with stdout is only needed with programs that use these descriptors incorrectly.