Built-in logging libraries offer more flexibility: you can set the log level of each module to avoid flooding your log files with everything's debug logs, for e

Built-in logging libraries offer more flexibility: you can set the log level of each module to avoid flooding your log files with everything's debug logs, for example. Or you want to write multiple log files with different settings. Also legacy; before systemd/docker/kubernetes, applications had to send to syslog themselves.