A very handy grep that you can use to cat your files without the hash (#) comments:

$ grep '^[^#]' /etc/systemd/timesyncd.conf

Produces only the lines that aren’t comments, eg:

FallbackNTP=0.debian.pool.ntp.org 1.debian.pool.ntp.org 2.debian.pool.ntp.org 3.debian.pool.ntp.org

Extending this to exclude lines where the hash isn’t the first character and have blanks before a comment, eg.

$ grep '^[[:blank:]]*[^[:blank:]#;]' /usr/share/postgresql/postgresql.conf

Shows only the active parts of the config, which in the case of postreSQL may not be many lines from a highly commented file.