[avian]

> few people read commit messages

That very much varies. In a project where 90% of commits are “fix”, “foo”, “commit”, etc. then yes. Nobody will ever read that (or do pretty much anything else useful with a VCS).

On the other hand, when every commit message is on the level, the yes, people do read them. Actually, first step when investigating any problem or trying to understand some code is to look at the commit log.

See e.g. Linux kernel or some of the Google-related open source projects (chromium, webrtc, etc.) for examples of good, long-form commit messages.