> And, at least with JIRA, if you name your branch such that it starts with the ticket id, it automatically picks up any pushed commits for that ticket. It's very useful.
I've been working at my current place of employment long enough to see them transition between several different issue trackers. The links to old issue tracker tickets no longer resolve, so it's definitely better to include a description of the issue directly in the commit message in addition to the link to the issue tracker.
When you do have those, then it's the ticket that gives the why's and how's. The commit messages do not have to be essays. And, at least with JIRA, if you name your branch such that it starts with the ticket id, it automatically picks up any pushed commits for that ticket. It's very useful.