I recently looked into disk usage of journald and was also shocked. My next step towards peace of mind is https://www.devuan.org/os/init-freedom
Will try it out as next distro for my Debian system, longtime experience with Void Linux (runit) on another box is great.
systemd-journald has one of the most deranged log file formats I have ever dealt with, and one of the worse user interfaces, too.
I am not again binary logs, or logs in a database. It's just yet another time I deal with good ideas implemented horribly, horribly badly when it comes to systemd.
Many applications hammer the disk even if the developers don't believe this is an issue, not only journald, unfortunately.
It's my third attempt to make my regular Linux desktop less disk-chatty. This is a huge issue for btrfs and for COW FS in general, because they have massive write amplification for small and frequent writes (38,7 TB written to my idle desktop SSD in 2 years).
If you're interested, here are my findings this time so far: